Added reference to xerces.Impl

git-svn-id: https://svn.apache.org/repos/asf/directory/studio/branches/studio-tycho@1643863 13f79535-47bb-0310-9956-ffa450edef68
Replaced SNAPSHOT by qualifier in the MANIFEST.MF files, added some missing imports (xerces, odfdom, poi)

git-svn-id: https://svn.apache.org/repos/asf/directory/studio/branches/studio-tycho@1643864 13f79535-47bb-0310-9956-ffa450edef68