make TCP in destiny optional
hwtimer.h remove cruft, document, rearrange

remove unsused hwtimer_t0* declarations
document hwtimer_now
move hwtimer_now outside the internal section
include version string
only add branch to version string if not in master
fix native stdlib.h include

Fixes segfault in OSX introduced by 45ffdea
Merge pull request #337 from LudwigOrtmann/hwtimer_cleanup

hwtimer.h remove cruft, document, rearrange
Merge pull request #351 from OlegHahm/tcp_optional

make TCP in destiny optional
Merge pull request #394 from LudwigOrtmann/native_fix_include

fix native stdlib.h include
Merge pull request #378 from OlegHahm/version_string

include version string
fix the bloody longterm vtimer bug

You know who you are, I'm looking at you!
add license header
fix grammar in license header
added vtimer_msg_receive_timeout
enable vtimer based timeout