Add possibilite rules
Infer "if" block
Add tests
about if
Gen
Infer ForIn
Add tests
Add REAME
Infer ForOf
Infer Function return type
Infer Range
update readme
Infer BinaryOps
README
Split type.coffee to type_walker and types
Refactor walking wip
Use currentScope.checkAcceptbleObject
Rename curentScope to scope
Refactor type_checker
Add test about types