ports/143589: [NEW PORT] devel/py26-gevent: Python co-routine networking library based on greenlet/libevent

[Peter Schuller]

Thanks for committing, but please note that as per previous PR history
this PR was blocking on devel/py-greenlet (because greenlet was
recently removed from pylib) which is ports/143610. Without it, this
submission was broken unless building against an older ports tree.

-- 
/ Peter Schuller