The aerogear-sync-server  repository contains a single server
implementation which is based on the 409 Conflict handling which is now
also available via the Forge plugin. So I'd like to remove the rest server.
There was also some early differential synchronization work done  which
is out dated and could be removed.
For those interested the experimental work that Luke and I have been
working on is in this branch  and I'd be happy to push it.