Stability improvements.
Some new python test scripts.
A few things exposed as prefs.
Allow "undo" to work by allowing a single collab client to
broadcast that intent to all other clients. This is one huge
plus to having the local client use a revert/unrevert model
of collaboration: synced shared undo state for all clients.
have redo working over the collab session aswell as the undo.
This is some fiddley stuff!
Now builds again if you dont have zmq installed.
Getting closer to a merge ready state.
cleaned up for merge
Merge remote-tracking branch 'upstream/master' into 2013marchcollab2

Conflicts:
	fontforge/collabclient.c
Merge pull request #510 from monkeyiq/2013marchcollab2

2013marchcollab2: Collab updates
I tested compilation sans collab by removing zeromq3-devel czmq-devel and rebuilding. Seems to all be in order.