1) Add integration tests running change replication over REST to verify
that access control at model level is correctly enforced.
2) Implement a new access type "REPLICATE" that allows principals
to create new checkpoints, even though they don't have full WRITE
access to the model. Together with the "READ" permission, these
two types allow principals to replicate (pull) changes from the server.
Note that anybody having "WRITE" access type is automatically
granted "REPLICATE" type too.
3) Add a new model option "enableRemoteReplication" that exposes
replication methods via strong remoting, but does not configure
change rectification. This option should be used the clients
when setting up Remote models attached to the server via the remoting
connector.