- new release, version 0.5
- IComparable on Node class
- better comparable implementation for Node, allowing for comparing
  types and values "correct", I think ...
- many more unit tests, plus cleaning up some of the existing ones
  all keywords now have their own unit test suite
- static constructor on Expression class
- support for empty start and end value on ranged iterator by omitting
  the number, which makes range default to 0-max-number, depending upon
  which part you omit
- more robust "add" keyword, only accepting nodes as source and
  destination expression
- "if" can now be an empty lambda object, with no children, and still
  be legal
- cleaned up Conditions, and created much more robust logic
- cleaned up "for-each", more robust now
- cleaned up "set", more robust
- "while" can not accept empty content