Enhances the metadata editor dialog to enable the user to edit NG-specific metadata.
attempt to add the default preferences to the songbird-prefs.js.in
added an escape to the previous use of double quotes.
Merge pull request #308 from luisgmarine/enhancedMetadataEditorDialog

Enhanced metadata editor dialog issue #225
update MPEG4_Expand_Ref.m4a reference file for taglib > 1.6.x
fix copying test files on darwin
clean up install.rdf's for apple extensions, add contributors