Suggestion: Improve the hint system

[craigbox]

I haven't played Minesweeper in a while and I'm enjoying figuring out why certain squares are safe by switching in and out of debug mode.

Another way to achieve this would be if the hint system would show why there are safe squares. There are three cases: you missed something obvious (e.g. there's a 2 with only 2 possible squares unflagged), or you have to do some pattern recognition/deduction to figure out why this square next to a number is either safe or unsafe.

(The hints should probably show in that order.)

Secondarily, a good way to make Kaboom into a minesweeper tutorial mode would be to have an option to have the hint always show.