This is a patch which will correct the issues some people 
have with python's handling of signal handling in threads. It 
allows any thread to initially catch the signal mark it as 
triggered, allowing the main thread to later process it. (This 
is actually just restoring access to the functionality that was 
in Python 2.1) The special SIGINT handling for the python 
readline module has been changed so that it can now see an 
EINTR error code, rather than needing a longjmp out of the 
readline library itself. If the readline library python is being 
linked to doesn't have the callback features necessary, it will 
fall back to its old behavior.