lookupContentType: Match known Content-Types with or without +xml suffix.
lookupContentType: Match known Content-Types with or without +xml suffix.

jscinoz/assetgraph,papandreou/assetgraph,jscinoz/assetgraph,papandreou/assetgraph,jscinoz/assetgraph,assetgraph/assetgraph,papandreou/assetgraph