** Changes in Allout

*** Topic cryptography added, enabling easy gpg topic encryption and
decryption.  Per-topic basis enables interspersing encrypted-text and
clear-text within a single file to your heart's content, using symmetric
and/or public key modes.  Time-limited key caching, user-provided
symmetric key hinting and consistency verification, auto-encryption of
pending topics on save, and more, make it easy to use encryption in
powerful ways.

*** `allout-view-change-hook' marked as being deprecated - use
`allout-exposure-change-hook' instead.  Both are currently being used, but
`allout-view-change-hook' will be ignored in a subsequent allout version.

*** Default command prefix changed to "\C-c " (control-c space), to avoid
intruding on user's keybinding space.  Customize the
`allout-command-prefix' variable to your preference.

*** Allout now uses text overlay's `invisible' property (and others) for
concealed text, instead of selective-display.  This simplifies the code, in
particular avoiding the need for kludges for isearch dynamic-display,
discretionary handling of edits of concealed text, undo concerns, etc.

*** Many substantial fixes and refinements, including:

   - repaired inhibition of inadvertent edits to concealed text
   - repaired retention of topic body hanging indent upon topic depth shifts
   - refuse to create "containment discontinuities", where a
     topic is shifted deeper than the offspring-depth of its' container
   - auto-fill-mode is now left inactive when allout-mode starts, if it
     already was inactive.  also, `allout-inhibit-auto-fill' custom
     configuration variable makes it easy to disable auto fill in allout
     outlines in general or on a per-buffer basis.
   - new hook `allout-mode-deactivate-hook', for coordinating with
     deactivation of allout-mode.
   - bulleting variation is simpler and more accommodating, both in the
     default behavior and in ability to vary when creating new topics
   - mode deactivation now does cleans up effectively, more properly
     restoring affected variables and hooks to former state, removing
     overlays, etc.
   - included a few unit-tests for interior functionality.  developers can
     have them automatically run at the end of module load by customizing
     the option `allout-run-unit-tests-on-load'.
   - many, many minor tweaks and fixes.  many internal fixes and
     refinements of docstrings.
   - version number incremented to 2.2