added support for the define expressions in the tag-parser
started implementing the applicative expressions. implemented fully but not tested: predicate, partially implemented the constructor.
implemented fully the applic expressions (for any number of variables
repaired wrong logic regarding detecting Applic expressions. also added support for Or expressions
added full support (tested ) for all the lambda expressions
add 'and' and MIT define form predicates (tested). also re-wrote the simple define predicate, added a utility predicate def_expr for recognizing both.

added also predicates for the 3 let expressions. although bugged.
add 'and' and MIT define form predicates (tested). also re-wrote the simple define predicate, added a utility predicate def_expr for recognizing both.

added also predicates for the 3 let expressions. although bugged. in addition also added cond predicate (tested)
debugged let and let* predicates. letrec is not working correctly yet
all predicates (besides quasiquates) are working correctly
Merge pull request #2 from amitaid/zelig

Zelig