Don't hardcode dwNumberOfProcessors=1 for Win32 anymore; the mutex/event code
is still far from perfect, but now good enough that I can't find any codecs
that breaks with this (tested on a quad with various codecs). This tells
codecs they can use more than one core if they want to (some already did, by
launching multiple threads even when told there was only a single core).
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@30926 b3059339-0415-0410-9bf9-f77b7e298cf2