the pascal parser uses an internal error handler to handle errors and exceptional conditions. If a valid token was read, it messages its values to an appropriate listener.
removed listeners.h & listeners.cpp source files. All listeners will be in psc.cpp
removed not-needed files
ParserMessageListener handles MessageType::Token & MessageType::SyntaxError message types
TokenExtractor is not a frontend class, but language-specific
skipws() function skips whitespace
abort on fatal error
pascal scanning for words, symbols, and strings
lexing numbers (under testing)
boost::variant replaced boost::any + many bug fixes in lexer
scanner test