New keybindings code and backend. New structs subnfunc for menu functions
and toggles and sc for shortcut keys, old 'shortcut' and 'toggles' structs are
gone.  The current implementation has a bunch of broken stuff (some of which is
documented in BUGS).  Updated nanorc.5 with some mostly complete documentation
on configuring.

Part 2 of commit since I accidentally did it in src/ the first time.  Yeah,
welcome back bonehead.


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@4216 35c25a1d-7b9e-4130-9fde-d3aeb78583b8
4 files changed