The new keymap functions

[Lars Ingebrigtsen <larsi@gnus.org>]

As previously discussed, we wanted to add make the Emacs key binding
machinery easier to understand, and go for a single syntax for bindings.
This entails adding a bunch of new functions, since the old functions
should continue to work as before.

The most difficult thing here is naming, of course, but after much
discussion, I've settled on these:

keymap-set
keymap-local-set
keymap-global-set
keymap-local-unset
keymap-global-unset
keymap-lookup

define-keymap and defvar-keymap keep their names, but use the
`kbd-valid-p' syntax.  In addition, `kbd' has been refactored, and the
new name `key-parse' has been defined -- which is like `kbd', but always
returns a vector.

Finally, the -unset functions remove the bindings instead of setting
them to nil.

I've added the functions and converted the few define-keymap instances
that are in-tree to the new syntax, but wanted to give all y'all a
chance to discuss this further for a couple of days before I push these
changes.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no