Corrected problem due to design flaw in Parser class;
Moved method definitions from parser.h to parser.cpp.
Explicited naming convention for macros;
Renamed function string_to to string_to_tuple in parser.cpp;
Added convention for mangling in mangling.txt;
Added structures that will be generated by the semantic analysis in ast.h
Corrected std::iterator_traits<position_iterator>::iterator_category to std::forward_iterator_tag
Added basic structure of symbols, operators and symbol table (for semantic analysis)
Added header utility/metaoperators.hpp, to automate the definition of
lexicographical comparisons in structures;
Added lexicographical comparisons to class Token (the comparison ignore position);
Added unit test to the Token comparison operators;
Restored test/main.test.cpp;
Modified makefile to make both a.out and test/test by default and run
the tests on `make test`;
Corrected recipe to clean and veryclean targets in makefile;
Corrected typos in ast.h.