minor changes according to 7a2cc4ae096a90308c026dd857e19b4489b162cf
clean up of ifdefs in transceiver module
Merge pull request #112 from OlegHahm/msb430_uart0

Changes according to the pull requests from https://github.com/RIOT-OS/boards/commit/dc5e7d7e1f62c787262a430d191764387c7242fd introducnig uart for MSB430 and changing the name of the terminal variable.
fix for #117 and position of preprocessor directives
some debug enhancements
removing residual breaks in switch-case statements due to #ifdefs
removed unused (and ambiguous) definitions of active_thread and sched_threads in kernel_init.c
moved prototype for sched_register_cb() from C file to header
Merge pull request #118 from OlegHahm/transceiver_cleanup

Transceiver cleanup
added documentation for sched.h
re-added the scheduler callback (the actual call was missing)
Merge pull request #134 from OlegHahm/sched_fixes

Scheduler callback