Add support to skip data load plugin

git-svn-id: svn://svn.openvpms.org/openvpms/maven/branches/1.8-dev@5962 9e4fa352-aafb-0310-9071-df624684024b
Merge remote-tracking branch 'remotes/1.8-dev' into 1.8-dev
Merge branch '1.8-dev'