Add regex parser
Add regexes for Python's grammar
Add main module for lexer
Add new lexer regexes
Completely replace LexerUtils; now fully compliant with lex spec
Add cautionary tale to top of LexerUtils
Source the "we do not have" list to README, where it belongs
Initial commit for lexer
Add function to emit tokens
Update lexer comments, indent issues, etc.
Add sketch of initial control logic of lexer
Add better newline token emission handling
Update indentation issues
Add function to lex a single line
Add initial sketch for most of lexer
Add to sketch of lexer
Begin to finalize lexer sketch