Is this macro in use at all?

I'm not sure if we should check for the result of pthread_join().
But how it was doesn't do that anyway.

This allows to build the threading module on Android. Android has
a little reduced implementation for POSIX threads.

This is a clean version of patches from
 Stephan Jauernick <info@stephan-jauernick.de> and
 Marvin Scholz <epirat07@gmail.com>.

This fixes missing includes of standard headers.
This seems to happened as a result of cleaning up the protocol code.