- made short keycode macros for the USB keycodes (under "lib/...")
- refactored "keyboard/.../layout.c", to make way for multiple layouts,
and to make it easier to read (by using short keycode macros)
- layout.h has a computed include line now, and the code (and layout
specific header stuff) is in a subdirectory. the makefile should
take care of which layout gets included and compiled
- changed kbfun_press() and kbfun_release() to be able to handle the
modifier keys (instead of requiring a separate function for the
modifiers)
- added a makefile variable for which keyboard gets compiled. even
though there's only one right now
