This change adds a keydown() function that is synchronized with events,
ie. it returns the key state as seen by previously read events.
It also completely eliminates low-level repeat events, which are not
very meaningul as the keyboard scan frequency goes up (and would be
meaningless if KEYSC interrupts were used), and adapts getkey() by
giving it access to the current driver time through pollevent().
* Now uses topti instead of fxlib for text (including MMU failure)
* Fit .pretext into 4k for everything before MMU succeeds
* A short version of sprintf() for dynamic messages
* Support a driver function, status(), to allow early driver debug
* Expose more useful platform information in <gint/mpu.h>
* Expose the first of a few CASIOWIN syscalls