make profiler a module

I tried to make the profiler of the msba2 a general module...

missing parts: `hwtimer_now_ach()` is a function in native, we should consider to run the hwtimer in its own thread (perhaps its possible to tell the compiler that this function should not get profiled)

how to build: build your project with -CFLAGS="-finstrument-functions" use `void profiling_stats(void)` to print stats

what do you think?