Heavily expand on the image docs
Merge branch 'master' into ws
Merge branch 'ws' of github.com:nitrogen/nitrogen_core into ws
Session handler more resilient of malformed state
Add to wf:to_existing_atom

With docs
Fix typo in #custom docs

Also expand a bit on the 'tag' semantics
Add notice about =wf:set= to image docs
Merge branch 'master' into ws

Conflicts:
	src/lib/wf_convert.erl
Websocket connectivity working.

Now it's time to redirect comet requests to the websocket system