posix: add semaphore implementation
remove sixlowpans own semaphore and use new riot semaphore in flowcontrol
fix spelling in msg.c
harmonize msg.c DEBUG statements

Use same order (function: [thread_name:] message) throughout msg.c.
Begin message with a capital letter.
make includes coding convention compliant
explain the "brainfuck condition"
fix spelling in msg.h
document msg_init_queue return values
remove race condition for good
clean up auto_init includes

Include headers only if respective module is built.
Fixes building for msb-430.
Prevents possible build breaks in the future.
Merge pull request #218 from mehlis/semaphore

posix: add semaphore
Merge pull request #275 from LudwigOrtmann/fix_msg_spelling

fix spelling and harmonize DEBUG statements in msg.[ch]
fixed sixlowpan address initialization

 * prevent that IPv6 address gets overwritten when configuring as adhoc router
 * additional debug information about assigned IPv6 addresses
fixed length for DAO ACK
use Makefile.base for shell_commands
Merge pull request #263 from OlegHahm/sixlowpan_fixes

sixlowpan address initialization
do not overwrite SRC in Makefile.base
Merge pull request #280 from LudwigOrtmann/auto_init_imports

clean up auto_init imports
Merge pull request #273 from LudwigOrtmann/uart0_cleanup

Uart0 cleanup
Merge pull request #285 from hper/rpl_fixes

fixed length for DAO ACK