`define-alternatives' bugfix and UI enhancement

* simple.el (define-alternatives): Call the selected command
interactively.  When setting `COMMAND--implementation' for the
first time, tell the user how to chose another implementation.
Enhance the docstring.
Spelling fixes.
Fix/enhance `define-alternatives' docstring again
Correctly handle reaching the end of the interval tree. (Bug#15344)
Correctly handle reaching the end of the interval tree. (Bug#15344)
Fix rst-mode deprecated keybindings
Fix MinGW64 porting problem with _setjmp.

Reported by Eli Zaretskii in:
http://lists.gnu.org/archive/html/emacs-devel/2014-01/msg01297.html
* image.c (FAST_SETJMP, FAST_LONGJMP): New macros, replacing
the old _setjmp and _longjmp.  All uses changed.
* lisp/emacs-lisp/edebug.el (edebug--display): Move protective let-binding
so it applies in the right buffer.
ChangeLog fixes
* epa-file.el: Respect buffer-file-format when writing

* epa-file.el (epa-file-write-region): Encode the region according
to `buffer-file-format'.  Problem reported at:
<http://sourceforge.jp/ticket/browse.php?group_id=2267&tid=32917>.
ispell.el (ispell-region): Reset `in-comment' for new line instead of `add-coment' (bug#13577).
Space before paren, updating recent change.
font-lock.el (font-lock-keywords): Fix typo in docstring

* font-lock.el (font-lock-keywords): Fix typo in docstring
(bug#16307).
simple.el (define-alternatives): Add 'definition-name to COMMAND-alternatives

* simple.el (define-alternatives): When creating the
COMMAND-alternatives variable, assign COMMAND as its definition
name so that `describe-variable' can relocate it.

See http://lists.gnu.org/archive/html/emacs-devel/2014-01/msg01340.html
ChangeLog fixes
* lisp/emacs-lisp/package.el (package-desc-keywords): New function.
(describe-package-1, package-all-keywords)
(package--has-keyword-p): Use it.
* lisp/indent.el (indent-rigidly): Set deactivate-mark to nil
in transient indentation mode.
ChangeLog fixes
src/ChangeLog: Fix typos.
Small doc/ copyedits

* doc/emacs/files.texi (File Conveniences):
* doc/emacs/misc.texi (EWW): Copyedits.

* doc/misc/Makefile.in (eww_deps): Does not depend on emacsver.texi.

* doc/misc/eww.texi: Comment.