Set mimeType correctly for Wikimedia Commons images
Added a few audio types to generic mimeType identifing function
Added ogg audio types, in preparation for harvesting audio from wikimedia
Merge pull request #43 from hyanwong/mimeType_additions

Added a few audio types to generic mimeType identifing function
Some refactoring of ContentManager based on work by hyanwong
Merge pull request #41 from hyanwong/wikimedia_mimeType

Set mimeType correctly for Wikimedia Commons images
Small tweak to XML validation code
Merge branch 'master' into data_harvest