Working model using FileTree + PatternSet for managing source documents
Added resources method to handle copying of additional resources to utputDir without having to resort to a seperate copy task
Removed 'sourceDocumentNames' method as it never was in any released version and is now superceed by 'sources'
Updated README with details of the 'sources' and 'resources' methods
Deleted unit test that are no longer relevant. Updated README with more notes on backwards-compatibility