on mod keys, register LGUI, LSFT etc. as normal mods
instead of weak mods:
- they won't be cleared when pressing another key (#188)
- they won't be cleared by layer switching
- LSFT(KC_LGUI) will now have the same behavior as LGUI(KC_LSFT)
- new macro_mods bit field for mods applied by macros
- weak_mods now only used for ACT_{L,R}MODS (i.e. LSFT, RSFT, LCTL etc.)
- clear the _weak_ mods on every key *pressed* such that LSFT etc.
can no more interfere with the next key
