Jarn-xmpp-collaboration

------------------

- Fix checksum bug preventing the shadow text to be applied if an error ever
occured.
[ggozad]

------------------

- Perform checksum checks on every patch. Deal with potential errors due to
network lag.
[ggozad]

- Use TinyMCE's raw instead of processed text. Improved reliability.
[ggozad]

------------------

- Major protocol update. Instead of sending message stanzas around, now iq
stanzas are used. This makes it possible to check for errors and synchronize
in certain edge cases. It also makes the protocol more in line with XMPP
conventions.
[ggozad]

- Reorganized and cleaned js code. The client protocol implementation is now
separate from the plone-specific parts allowing code reuse and improving
readability.
[ggozad]

- Notify user when others are joining/leaving the node.
[ggozad]

------------------

- Documentation updates.
[ggozad]

- Fix js error when user has left collaborative editing.
[ggozad]

------------------

- Simplified configuration and fixed confusing typos in the registry
[ggozad]

------------------

- Configure the component/server password and connection port in p.a.registry.
[ggozad]

- Dexterity content type support.
[davisagli, ggozad]

- Generalized ATContentTypes support.
[ggozad]

- Provide visual feedback when a user updates a node.
[ggozad]

- JS cleanup.
[ggozad]

- Test coverage.
[ggozad]