Lexer now tracks first column of tokens.
Scrap unused code from lexer. Fix some pylint warnings. Beautify.
First crude version of error reporting using logging module
Logging is now class-based. Add INFO messages to lexer.
Add static analysis targets to Makefile
Code grooming
Fix bad spec URL. Fix some pylint warnings
Merge pull request #7 from Renelvon/logger

Use Python logging for error reporting. Cleanup code. Automate some static analysis.