Lexical Analysis: Fixes and improvements.

- Fixed an issue where “3x” is considered as a number and an ID (fixes
#1).
- Added support for C-like comments (“/**/”).
- DFA transition table format improvements:
- Start node is now alone in the first line.
- Final nodes now have a separate line (the second), with “ - ” divider
(including spaces), to support spaces in node description.