It Lives 2: Live Harder

It now works properly as far as I can tell, though certain features are
not fully implemented. The output .xml correctly 'optimises' by not
writing redundant phrases across difficulties. Testing is still
necessary.

Not yet implemented (probably not conclusive):
- Anchors (Parsing or Auto-writing)
- Handshapes (Same again)
- Techniques (Not convinced it's correctly identifying them)

Further development:
- Change use of VectorEmptyException to be less... unrelenting.
- Incorporate additional variables for stuff like start-offset.
- Improve start-of-file metadata (Average Tempo, for example).