fix register_interrupt callback parameter
fix hwtimer_arch_set_absolute return value
fix broken warning
fix warning for sa.sa_sigaction assignments
fix unused startup parameter warnings
fix unused parameter warning in posix-rtc.c
Change interface cb parameter to function pointer
Merge pull request #151 from LudwigOrtmann/issue_147

fixes Issue 147
Merge pull request #157 from mehlis/crypto

remove broken warning, this is a compiler bug not a RIOT problem