added pl0 examples
added compiler example for code generation
added some skeleton to CodeGenerator
added CodeGenerator class
partial implementation of methods
added generation of PL0 symbols table, and implemented PL0 output writer method
added label generation functions
added code generation for storing variables
corrected some compilation errors
added test file for code generation
added more code genaration, added ignore space at BOF
added label modifier method and generators for parameters
added code generation todos, and some semantic check fixmes
corrected return type matching messages
implemented code generation for expressions, functions and ifs
added hello world test program
replaced ltoa calls
added restriction for void type in expression
added check of function type in arguments
added checks for functions with lvalue not used