Printing warnings. Now we have a SymInfo argument 'used' that indicates if an identifier is ever used.
Now marking when using a variable or function. new Error check: function UsedNotImplemented. Now we check warnings after checking the program for errors. warning checks: identifier DefinedNotUsed, function DefinedNotImplemented. processDeclaration now returns 'Checker Bool', true if it ADDED the identifier to the SymTable. Fixed some Styling.
processDeclaration better documented