v3, 4 partsSupport non-WIN32 systems lacking poll()

Here's now my series or patches to make the win32 implementation of poll() available to other platforms:

1 - poll() exits too early with EFAULT if 1st arg is NULL, as discussed with Paolo Bonzini from the gnulib team 2 - make poll available for other platforms lacking it by moving it into a separate directory and adjusting Makefile 3 - fix some win32 specific dependencies in poll.c by #ifdef the inclusion of two header files 4 - make poll() work on platforms that can't recv() on a non-socket, namely HP NonStop

Bye, Jojo