tui: Rework and common code suppression (closes #2)

All the modules now have:
* A version for RTOS environments. These functions hold the program
execution, so an RTOS is needed to ensure multithread.

* A demonised version. These functions DO NOT hold the program execution.
They make a litle job at a time instead. This way we can call them in
the main loop without an RTOS.