Enforce NodeReplicationPolicy in CN

[taojing2002]

The NodeReplicationPolicy section has been implemented in Metacat. The first around supports allowedNode and allowedObjectFormat. The ticket is here.

However, we found that the cn part should be implemented as well. If CN has no knowledge about allowedNode and allowedObjectFormat of the given MN, it will send anything to that MN. However, that MN will reject most of replication requests if they don't come from the allowedNode. This will lead the MN being put into the black list. So cn should only send the replication requests which come from allowedNode with allowedObjectFormat.

[mbjones]

This has become more crucial as some replication nodes start to fill up. See also Metacat issue NCEAS/metacat#2284 on spaceAllocated and #3 for better targeting replicas.