Major refactoring of code structure (not logic!).

Added general RubyParser constructor.
Moved actions out of Parser constructor.
Moved Builder out of rules namespace.
Hide Builder nodes stuff in a namespace.
Tweaked Lexer a little to reflect new RubyParser
update simple launchers
make test -> make debug
move default filename out of lexer
handy methods
false to be the mark of failure
all this dramatically simplifies the racer wrapper
remove this ugly hack