dont invoke super ctor if there are no base fields (fixes System.ValueType base type case)
explicitly reference Boo.Lang.PatternMatching
support 'let' and other constructs inside 'data' bodies
move tokens macro to Boo.OMeta.Parser as it's strongly tied to the grammars there
code gardening
give next known position when prepending
support for using member generating macros such as 'let' inside 'ometa'
position and success primitives
remove boilerplate comments
ToString for debugging
Merge pull request #5 from bamboo/master

Boo.Adt fix and Boo.OMeta improvements