MH-9489 -- created mediapackage to DOM serialization method based on JAXB

git-svn-id: http://opencast.jira.com/svn/MH/trunk@13968 e6edf6fb-f266-4316-afb4-e53d95876a76
MH-9483 -- fixed integration test through MH-9489

git-svn-id: http://opencast.jira.com/svn/MH/trunk@13969 e6edf6fb-f266-4316-afb4-e53d95876a76