tests: Read-only replication tests now calls xtfs_scrub after adding a

full replica. The test will fail if xtfs_scrub did not mark the second
replica as "complete" at the MRC.


git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@3300 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534