Jantzen Owens

I'm working through Hands-on Rust and have the beginning dungeon crawler window with moveable character (page 88). For posterity, the latest repo commit is [0d2d5e6](https://github.com/amethyst/bracket-lib/commit/0d2d5e6a9a8e7c7ae3710cfef85be4cab0109a27). No crash on mouse over...