EPUB Reader: Added EPUB reader
Except Compat: Updated to export more module functions
Options: Added option to turn on epub html extensions
HTML Reader: Extended HTML Reader to recognise EPUB specific elements
HTML Reader: Added support for anchors on links and list items
HTML Reader: Added ability to read MathML formatted <math> blocks
EPUB Reader: Integrated into program
EPUB Reader: Added tests
README: Updated with EPUB information
EPUB Reader: Now uses the new MediaBag for images
Merge branch 'epubend' of https://github.com/mpickering/pandoc into mpickering-epubend

Conflicts:
	pandoc.cabal
Use texmath 0.7 interface.
README: Removed duplicate ref of [EPUB].
HTML reader:  ignore <?xml..> and <DOCTYPE..> tags.

Previously they were parsed as raw.