2.0.0 Beta 3

Lots of fixes in this pre-release.

• Change rend to lform on slur.
• Change headshape to head.shape on note.
• Better tuplet and beam handling.
• Fixed log message formattings
• Removed layer on clef.
• Added Batch Processing plugins
• Using the 7.1+ AccidentalIsVisible method (!!)
• Adjusted the metadata for the plugin
• Appoggiatura and Acciaccatura are now properly encoded
• Encoding of stem direction
• Simplified tie handling
• Vertical lines ('barlines') are encoded
• Line durations are always greater than 0.
• Slurs can have tstamp2 now
• Octave-displaced clefs now affect the notes on the staff
• (some) MIDI information is now stored
• libmei bug in creating comments is fixed
• Front matter (cover pages, etc.) is handled
• New method to convert Units to typographic points
• Improved (prettier) XML output

And lots of other minor bug fixes.