doxygen

latch & latch-to-lock

api:
 - xkb_layout_index_t
 - xkb_level_index_t
 - group -> layout??
 - xkb_map* -> xkb_keymap*
 - xkb_key* -> xkb_??
 - xkb_log_* -> xkb_context_??
 - export keymap group/level api
 - RMLVO enumeration?
   + needs XML :(

larger group numbers

merge ExprResolveKeySym and LookupKeysym?

~/.xkb/rules.local + ~/.xkb/keymap.local
  - /etc/default/keyboard?
  - accept NULL for RMLVO compilation

remove core mods
 - xk-c patches

xkeyboard-config:
 - flatten compat and types
 - kill modMapMods, make everything explicit
