Implements getppid in the os module on Windows systems. The getppid 
function was only available on Unix like systems, this diff patch brings 
this functionality to Windows systems.  This function will return the 
parent process Id, upon error it will return -1.  This differs from the 
Unix implementation that never fails.  Due to the way Windows returns the 
parent process Id, a never fail guarantee can not be made.  It should only 
fail in low memory conditions.  This patch is on the latest svn trunk (	
http://svn.python.org/projects/python/trunk).  This implementation should 
port to any python version (older or newer).  I have personally tested it 
against Python 2.5.4, 2.6.2, 3.1, and the aforementioned svn trunk.