Added grammer rules and classes for Bool and Str
Fixed grammer mistakes and generated new parser
Forgot to add files
Added generics to Expr types
Revert "Added generics to Expr types"

This reverts commit 4a71ebd3e8f2e1abe75fb6029b173bd5f989977d.
Re-added antlr library
Pulled some more superclasses up.
Made some more refactorings
Worked further on questions and conditionals
Implemented computation, now for some more unit tests.
Form is now the starting symbol of the language. Created helper functions in TestParser superclass for easily testing forms, statements and expressions.
Refactored some more
Splitted out and added some more unit tests
branch test

branch test ruudvanderweijde
removal of jacc
added antlr 3.5
rewrite of grammar (after github for windows killed all my changes)
first creation of classes
moved expression to expr package
created binary and unary classes
More AST implementation
Setting of values, adding getters
First try to implement visitor
update of UnitTests!