bug#22334: 25.1.50; Better sorting of blocks in describe-bindings

[Eric Abrahamsen]

When using `describe-bindings' to see the current key bindings in
effect, I'd like the major mode bindings to be sorted to the top of the
buffer, followed by the minor modes. Right now the sorting of blocks
seems random, though every time the top block is twenty screens or so of
self-inserting bindings (or maybe it's compose sequences?) which are
never what I want to see, and are a pain to scroll past. While we're at
it, minor modes with no bindings in effect could just as well be
omitted.

A small improvement, but I hope worth making!



In GNU Emacs 25.1.50.2 (i686-pc-linux-gnu, GTK+ Version 3.18.6)
 of 2016-01-06 built on pellet
Repository revision: 6a311d2072b8a4ea530d9a541e661a8ad11bb1d7
Windowing system distributor 'The X.Org Foundation', version 11.0.11800000
Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LC_CTYPE: zh_CN.UTF-8
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix