v0.3.1

This is a patch release based on feed back from @KrisKennaway !

• Support parsing '?' tokens, which is a shorthand for 'PRINT'. PR #19
• Improve error reporting when parsing fails. Issue #20

This project is split into three components:

• A Java API. See the README for an overview.
• A BASIC tokenizer (bt) command-line tool. See the README for tool usage examples.
• A Shape Table (st) command-line tool. See the README.

Commits between v0.3.0 and v0.3.1