Hacked around what I think is a wx bug where on maximize, the sizer's size isn't the same as the panel's. This fixes the "font is sized for the last maximize/restore size" issue. Fixes #3.
Also Fixed #11 by forcing a Layout after marking it 'Done!'
Added a different colour for Break Time to be obvious. Restore to the normal colour on next round/restart. Fixes #10 .
Renamed "Restart" to "Reset" (because that's what it does) and added tooltips to relevant buttons.