Tuning of serial related things

* Update intefaces/communication.hh
* Rename methods in serial.hh and touchscreen4d.hh
* Small edits to regiester generation scipts
* Update autounion
* Update effected examples
Tune makefile. Tune yaal/core/cpu.

 * Support human readable F_CPU
 * Correct typo devider -> divider
Reimplement cpu prescaler system using frequency instead of divider.
Add way to get F_CPU at runtime. Update Serial.setBaud to work at runtime

* If YAAL_UNSTABLE_F_CPU is set, then cpu.clock.get() will return F_CPU at time of call.
  If that macro is not set, it returns compile time F_CPU
  This feature to work correctly at least one of F_CLOCK, F_CPU is needed. You should provide F_CLOCK as crystal speed and F_CPU as initial clock speed.

* Serial has new setBaud method, which should be very fast also when cpy.clock is dynamic (runtime) and/or baud rate is not combile time constant.
Interfacces: Split StreamableInterface out of communication
Fix serial.hh with atmega32u4