Ole Richter

now builds fine in the master branch with `cmake` and `make xycecinterface`, thanks a lot for all the effort!

If you have time for it that would be obviously amazing, otherwise I will do it after we send the chip off 1.5 weeks and use it to learn more...

if you build with ```cmake [...] -D CMAKE_C_FLAGS="-D_POSIX_C_SOURCE=199309L" [...]``` or ```make config [...] CONFIG_FLAGS="-D CMAKE_C_FLAGS=-D_POSIX_C_SOURCE=199309L"``` you should be able to build without problem, Its a POSIX version problem at least...

@rmanohar the pull request would now be ready for your review, let me know if i shoud rework something, in case you want to merge i made a list of...