Changed the parameter 'char * data' of process_start to the
type process_data_t. This was an artifact when the choice was
made to use the void * type for the data parameter in processes.

Changed parameter 'void * data' of process_post_synch to
process_data_t for consistency.

Checked all the uses of process_start() in contiki and fixed casts
of the data parameter.
Removing trailing whitespaces
Correct several doxygen tags (\file)
Merge pull request #696 from sieben/doc

Correct several doxygen tags (\file,...)
Merge pull request #722 from royscheefhals/contiki-fix

char * data to void * data parameter in process_start
aducrf101: Rearrange stack and heap to maximize available stack space

Stack now starts at the top of RAM, heap starts after BSS, and
they grow towards each other.
aducrf101: Add stack pointer sampling, to help debug overflows
aducrf101: Adjust default buffer sizes to fit better in available RAM
Merge pull request #759 from jimparis/aducrf101-fix-stack

ADuCRF101: Fix stack/heap overflow
Merge remote-tracking branch 'contiki/master' into develop

Conflicts:
	cpu/stm32w108/hal/micro/micro-common.h