enable/fix links on about page. why don't people test that stuff when they insert it? it's just one click...
fix ancient issue with hedgehogs sliding through/into think gaps; fixes
issue #542; could and should be optimized (also to make sure that hogs can't slide through little pixel turds) - feel free to do so =P
More flagging of Land values. Also use less than for tests of non-terrain, instead of "and $FF00 = 0". Saves a couple of ops, which actually matters a small amount in a few places.