bug#6068: Please learn Emacs to distinguish between visible and active windows

[Lennart Borgman]

The function make-frame-visible also makes the frame active. That is
not always what you want.

Could we please add a new parameter ACTIVATE to this function and let
it default to t for interactive use?

The changes needed to support this seems small. The function
x_make_frame_visible needs a new parameter ACTIVATE  to support this.
(On w32 it is a very small change, but I do not know about X.)

The reason to support it is that it makes it possible to make better
in place completion (compare
http://www.emacswiki.org/emacs/CompanyMode). The current
implementations tends to use overlays. This solution breaks down
currently when there are invisible parts in the buffer. I think a
popup frame would be easier.