Modifying grammar - several simple rules now have a semantic value of string;
Fixed missing method exceptionHandler problem with newer bisonc++ version (4.02.01);
Added StringList to parser-preincludes;
Finished implementing simple semantic values for rules leading to Variables creation;
Fixed error in Variable::Ptr declaration;
Added variables map and AddVariable method to Namespace;
Added semantic code to grammar for creating Variable and adding them to the namespace;
Removed prints from grammar rules
Changed Namespace attr Variables to GlobalVariables;
Added getter methods for Variables in Namespace;
Implemented Variable unit tests
Refactored a little
Fixed conflicts from rebase