renaming rop chapters to start with rop-

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1555546 13f79535-47bb-0310-9956-ffa450edef68
transferring old ROP docs

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1555547 13f79535-47bb-0310-9956-ffa450edef68