at86rf231 TX and RX

driver is using vtimer instead of hwtimer_ functions, TO CHECK

vtimer debug function prototype fix

Hwtimer fixes

add sha256 implementation

add oneway calloc

fix for #25 by using mutexes for hwtimer_wait

initial bloom filter import

fix changed prototype parameter 1 of thread_stack_init from void* to void(*)(void)

remove superfluous semicolons

Tell Doxygen to ignore __attribute__

Doxygen can't handle it properly (see
http://doxygen.10944.n7.nabble.com/struct-attribute-packed-not-working-td2666.html)

fix warnings from #62

Define phony make targets

added debug output for sending IEEE802.15.4 frames

Update .gitignore

Milestone 1 0 fixes

in msg_send_receive: return result from msg_send

Refactoring and Fixing of sixlowpan module

NOTE: this commit introduces a kernel API change for mutex_unlock