Log Message:
Update emacs-snapshot to 24.3.50.20130207.

Patches provided by Makoto Fujiwara in PR 47552 and modified by me.

Notable changes since 24.3:
** `apropos-variable' is now `apropos-user-option'
** `eval-defun' on an already defined defcustom calls the :set function,
   if there is one.
** The option `set-mark-default-inactive' has been deleted.
   This unfinished feature was introduced by accident in Emacs 23.1;
   simply disabling Transient Mark mode does the same thing.
** `initial-buffer-choice' can now specify a function to set up the
   initial buffer.
** ACL support has been added.
** New option `scroll-bar-adjust-thumb-portion'.
** Improved fullscreen support for Nextstep (Mac OS X).
** New commands `toggle-frame-fullscreen' and `toggle-frame-maximized',
   bound to <f11> and M-<f10>, respectively.
** Delphi mode is now called OPascal mode.
** jit-lock-debug-mode lets you use the debuggers on code run via jit-lock.
** completing-read-multiple's separator can now be a regexp.  The
   default separator is changed to allow surrounding spaces around the
   comma.

See share/emacs/24.3.50/etc/NEWS for the complete list of changes.