Add comments to easier find errors.
Update error messages to use new methods
Add suggestions to error messages
Fix inconsistencies in error positions
Add support for multi-line suggestions
Add size field to tokens
Add utility methods to help generate suggestions
Improve lexer error messages
Improve expected token parser error messages
Represent tokens as doubly-linked list
Improve parser error messages
Add levenshtein distance method
Improve identifier resolution error messages
Move errormessages stuff into separate module and compile it to JavaScript
Remove old class syntax and unused methods.
Improve error messages.