This commit introduces three timer driver changes:
* Export the definitions of the timer structures to a detailed header at
<gint/mpu/tmu.h>, and re-use them in the driver.
This integration is still limited as the driver keeps its own address
definitions and event codes.
* Clean the timer stop routine that is used in the interrupt handler. Up
until now the interrupt handler would only stop TSTR, which is not
enough to cleanly leave the timer (need TCOR=TCNT=-1) and is not even
sound with respect to gint's semantics as UNIE stays enabled so the
timer is not made available again.
The interrupt handler now calls into C code when the timer stop
condition is met (callback returns non-zero) to keep this clean. This
unsurprisingly solves problems that occurred in certain situations
when a timer was used repeatedly.
* Expose timer addresses using a timer_address() function, compensating
for the lack of address definitions in <gint/mpu/tmu.h>. This
interface is likely to evolve in the future to better integrate the
address in the MPU headers and move them out of the driver.
* 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
