Partial revert of 85b7eca1

Fixes #1197.

native: add missing include

crash.c was missing native_internal.h

Zolertia Z1 port for RIOT OS

Add process indicator to compile_test.py

core: and cpu: Added NORETURN to functions that should not return

make: print error if make was executed in the root

Fixes #1104, alternative to #1178.

test:test_vtimer fixed initializer and Wformat warnings

Native license unification

 sys/ping/ping.c: malloc size of type, not size of pointer

unittests: Unittests for core module data strutures

msp430: fix missing members in `struct tm`

native: initialize maybe uninitialized variable

Fix doxygen comments for hwtimer.h, queue.h and io.h

Native minifix

board: Initial import of the UDOO board

blacklisted for:
- ccn-lite-client
- ccn-lite-relay
- rpl_udp
- test_net_if
- test_pnet

core: improved doxygen documentation

- fixed comment style and bracketing
- disabled newlib nano, added mac support
- fixed OSX compatibility in Makefile.include

github: added CONTRIBUTING.md

improved files complient to issue #950
- thread.h
- flags.h
- debug.h
- crash.h

boards: fix license headers to LGPL