Add UI support for field mapping

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/branches/CONNECTORS-954@1603678 13f79535-47bb-0310-9956-ffa450edef68
Complete parameter mapping UI

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/branches/CONNECTORS-954@1603681 13f79535-47bb-0310-9956-ffa450edef68