Provide mouse dragging and resizing of frames.  Allow resizing
frames proportionally.  Provide additional functionality for
child frames.

* lisp/frame.el (frame-border-width, frame-pixel-width)
(frame-pixel-height): Alias to `frame-internal-border-width',
`frame-native-width' and `frame-native-height'.
(frame-inner-width, frame-inner-height, frame-outer-width)
(frame-outer-height): New functions.
* lisp/minibuffer.el (completion-auto-help): Fix typo.
* lisp/mouse.el (mouse-drag-line, mouse-drag-mode-line)
(mouse-drag-header-line): Allow moving a frame by dragging the
mode line of its bottommost window (on a minibuffer-less frame)
or the header line of its topmost window.
(mouse-drag-vertical-line): Mention argument in doc-string.
(mouse-resize-frame, mouse-drag-frame, mouse-drag-left-edge)
(mouse-drag-top-left-corner, mouse-drag-top-edge)
(mouse-drag-top-right-corner, mouse-drag-right-edge)
(mouse-drag-bottom-right-corner, mouse-drag-bottom-edge)
(mouse-drag-bottom-left-corner): New functions for resizing a
frame by dragging its internal border together with
corresponding key bindings.
* lisp/tooltip.el (tooltip-frame-parameters): Add
'no-special-glyphs' to default parameters and update version
tag.
* lisp/window.el (frame-auto-hide-function): Add choice to make
frame invisible and update version tag.
(window--delete): Handle 'auto-hide-function' frame parameter.
(window--maybe-raise-frame): Respect 'no-focus-on-map' and
'no-accept-focus' frame parameters.
(display-buffer--action-function-custom-type): Add
`display-buffer-in-child-frame'.
(display-buffer): Mention `display-buffer-in-child-frame' in
doc-string.
(display-buffer-in-child-frame): New action function for
`display-buffer'.
(window--sanitize-margin): Return zero when MARGIN cannot be
sanitized.
(fit-frame-to-buffer): Major rewrite to handle child frames and
'fit-frame-to-buffer-sizes' and 'fit-frame-to-buffer-margins'
frame parameters.
(window-largest-empty-rectangle--maximums-1)
(window-largest-empty-rectangle--maximums)
(window-largest-empty-rectangle--disjoint-maximums)
(window-largest-empty-rectangle): New functions.

* src/dispextern.h (WINDOW_WANTS_MODELINE_P)
(WINDOW_WANTS_HEADER_LINE_P): Remove.  Functionality is now
provided by corresponding functions window_wants_modeline and
window_wants_header_line in window.c.  Adjust users.
* src/dispnew.c (adjust_glyph_matrix)
(buffer_posn_from_coords): Use window_wants_modeline and
window_wants_header_line instead of WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P.
* src/frame.c (keep_ratio): New function.
(adjust_frame_size): Call keep_ratio for each of F's child
frames.
(make_frame): Initialize no_special_glyphs slot.
(frame_internal_border_part): New function.
(Fframe_pixel_width, Fframe_pixel_height, Fborder_width): Rename
to Fframe_native_width, Fframe_native_height mand
Fframe_internal_border_width.
(frame_parm_table): Add Qno_special_glyphs entry.
(frame_float_type): New enumeration type.
(frame_float): New function to handle frame size and position
ratios.
(x_set_frame_parameters): Handle size and position ratios.
(x_set_no_special_glyphs): New function
(x_figure_window_size): Handle size and position ratios.
(syms_of_frame): Add Qdisplay_monitor_attributes_list,
Qno_special_glyphs, Qframe_edges, Qkeep_ratio, Qwidth_only,
Qheight_only, Qleft_only and Qtop_only.
* src/frame.h (internal_border_part): New enumeration type.
(struct frame): New slot no_special_glyphs.
(FRAME_NO_SPECIAL_GLYPHS): New macro.
* src/keyboard.c (internal_border_parts): New array constant.
(make_lispy_position): For frames with border dragging enabled
return internal border part.
(syms_of_keyboard): New symbols Qdrag_internal_border,
Qleft_edge, Qtop_left_corner, Qtop_edge, Qtop_right_corner,
Qright_edge, Qbottom_right_corner, Qbottom_edge and
Qbottom_left_corner.
* src/minibuf.c (read_minibuf_unwind): When exiting the
minibuffer deal with frames that have the 'minibuffer-exit'
parameter set.
(syms_of_minibuf): New symbol Qminibuffer_exit.
* src/nsfns.m (frame_parm_handler): Add entry for
x_set_no_special_glyphs.
(Fx_create_frame): Handle 'no-special-glyphs' parameter.
Intitialize new cursor types for dragging frame borders.
* src/nsterm.h (struct ns_output): Add new cursor types for
dragging frame borders.
* src/w32fns.c (w32_frame_parm_handlers): Add entry for
x_set_no_special_glyphs.
(Fx_create_frame): Handle 'no-special-glyphs' parameter.
Intitialize new cursor types for dragging frame borders.
* src/w32term.h (struct w32_output): Add new cursor types for
dragging frame borders.
* src/window.c (coordinates_in_window)
(Fwindow_line_height, window_internal_height): Use
window_wants_modeline and window_wants_header_line instead of
WINDOW_WANTS_MODELINE_P and WINDOW_WANTS_HEADER_LINE_P.
(Fwindow_lines_pixel_dimensions): New function.
(window_parameter): New function.
(Fwindow_parameter): Call window_parameter.
(window_wants_mode_line, window_wants_header_line): New
functions replacing the macros WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P from dispextern.h.
(syms_of_window): New symbols Qmode_line_format and
Qheader_line_format.
* src/window.h: Reorganize and re-comment macros.  Use
window_wants_modeline and window_wants_header_line instead of
WINDOW_WANTS_MODELINE_P and WINDOW_WANTS_HEADER_LINE_P.
(MINI_NON_ONLY_WINDOW_P, MINI_ONLY_WINDOW_P): Minor rewrite.
(WINDOW_BUFFER): New macro.
(WINDOW_BOX_LEFT_EDGE_COL, WINDOW_BOX_RIGHT_EDGE_COL): Remove.
* src/xdisp.c (window_text_bottom_y, window_box_height)
(window_box, start_display)
(compute_window_start_on_continuation_line)
(try_cursor_movement, redisplay_window)
(try_window_reusing_current_matrix, try_window_id)
(display_line, expose_window): Use window_wants_modeline and
window_wants_header_line instead of WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P.
(pos_visible_p, display_mode_lines): Respect W's
'mode-line-format' and 'header-line-format' window parameters.
(init_iterator): Use window_wants_modeline and
window_wants_header_line instead of WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P.  For tip frames respect
no_special_glyphs value.
(note_mouse_highlight): Set frame border cursors when on
internal border.
(x_draw_right_divider, x_draw_bottom_divider): Try to improve
drawing of window dividers.
* src/xfns.c (mouse_cursor): Add entries for border parts.
(mouse_cursor_types): Add entries for cursor types to drag
frame borders.
(INSTALL_CURSOR): Add entries for new cursor types to drag
frame borders.
(Fx_create_frame): Handle 'no-special-glyphs' parameter.
(x_frame_parm_handlers): Add entry for
x_set_no_special_glyphs.
(Vx_window_left_edge_shape, Vx_window_top_left_corner_shape)
(Vx_window_top_edge_shape, Vx_window_top_right_corner_shape)
(Vx_window_right_edge_shape)
(Vx_window_bottom_right_corner_shape)
(Vx_window_bottom_edge_shape)
(Vx_window_bottom_left_corner_shape): New variables.
* src/xterm.c (x_free_frame_resources): Remove new cursors for
dragging frame borders.
* src/xterm.h (struct x_output): Add new cursor types for
dragging frame borders.

* doc/lispref/display.texi (Size of Displayed Text): Document
`window-lines-pixel-dimensions'.
* doc/lispref/elisp.texi (Top): Add entry for "Mouse Dragging
Parameters".
* doc/lispref/frames.texi (Frame Size): Replace
frame-pixel-width/-height by frame-native-width/-height.  Add
frame-inner-width/-height and frame-outer-width/-height docs.
(Position Parameters): Describe specifying position as ratios.
Clarify remark about positions relative to bottom/ridge display
edge.
(Size Parameters): Describe specifying sizes as ratios.
Describe 'fit-frame-to-buffer-margins' and
'fit-frame-to-buffer-sizes' parameters.
(Layout Parameters): Describe 'no-special-glyphs' parameter.
(Frame Interaction Parameters): Describe 'auto-hide-function',
'minibuffer-exit' and 'keep-ratio' parameters.
(Mouse Dragging Parameters): New section describing
'drag-internal-border', 'drag-with-header-line',
'drag-with-mode-line', 'snap-width', 'top-visible' and
'bottom-visible' parameters.
(Management Parameters): Mention that `override-redirect' has
no effect on MS Windows.
(Font and Color Parameters): Mention child frames for `alpha'
parameter.
(Child Frames): Rewrite section with description and cross
references to new frame parameters added.
* doc/lispref/modes.texi (Mode Line Basics): Mention
'mode-line-format' and 'header-line-format' window parameters.
* doc/lispref/windows.texi (Resizing Windows): Mention effect
of `fit-frame-to-buffer-margins' for child frames.
(Display Action Functions): New action function
`display-buffer-in-child-frame'.
(Quitting Windows): Mention `make-frame-invisible' as optional
value of `frame-auto-hide-function' and `auto-hide-function'
frame paameter.
(Coordinates and Windows): Describe new function
`window-largest-empty-rectangle'.
(Window Parameters): Describe new parameters 'mode-line-format'
and 'header-line-format'.  Index all window parameters described
in this section.