Basic UART debug interface
* Use the P10.4 and P10.5 pins
* Send back received text from host
Add function to write on the UART debug interface
Basic logging support
* Configuration flag to enable/disable the code
* Custom sprintf implementation
* Access synchronized with a Mutex
* Automatic EOL characters
* Log function defined to do nothing when disabled
Add function documentation for UART code
Switch to UCA1 (pins P5.6 and P5.7)
* Fix documentation
Merge branch 'feature/uart-logging'

Conflicts:
	include/config.h.in