[opwig] modified grammar files to support function-definition (without semantic values yet)
small code refactor on variable unit tests;
[opwig] Implemented semantic action for function-definition;
Updated md::Function to have bools for is_(default|delete|declared|defined);
Updated Utilities::JoinDeclarations so that it checks if a function was defined or declared before declaring it;
[opwig] Implemented function-definition related unit tests;
Fixed ignored_code grammar rule to accept TYPE and CONSTRUCTOR NAMEs and '=' as separator;
Fixed type grammar rules to accept PRIMITIVE and VOID keywords as types;
Fixed md::Function to set default value of some boolean attributes;
Disabled parser debug output;
Merge branch 'functiondefinition' into dev