Initial release

This marks the first release of Regexer.

Right now you can tokenize a regex, and parse that into an AST.
Manipulation of that AST isn't really stable, and might not work properly. But if you need it to analyze the regex, this release should suffice.

Not yet supported:

• POSIX class notation
• comments
• delimiters that have a diferent closing tag ({, [, (, and <).