refactored Type, split types into types allowed as param types and allowed as result type
refactored/simplified IllegalReturnTypeException
added more tests for FunctionFactory
renamed SyntaxParser -> ModuleParser
refactored ModuleParser
added TestingModule.testingModule() factory method with varargs
refactored FunctionsCollector
renamed TestingModule.testingModule(...) -> TestingModule.module(...)
added missing guice annotations to Problems/ProblemsListener
refactored ImportedFunctionsInitializer -> ImportedFunctionsProvider
added missing @Inject in some classes
fixed wrong exception messages in InvalidExpression