Version 0.9 of Lily. Major changes:
* Addition of __line__ and __file__ keywords that map to expected values.
* Emitter now handles blocks as a struct, instead of a series of 4 or so
  stacks. Much saner.
* Fix subscript assign to be less broken. Update nility and such.
* for..in implemented. It takes an integer start, stop, and optional integer
  increment (the by value). Can go up or down.
* Integers can be cast to and from numbers.
* Signature collection in parser rewritten to not use the signature stack by
  default, but as a fallback. A bit simpler.
