working! cleaned up a bit and found a silly bug

one bug left to fix before it's actually doing what it's supposed to

scanning at about 140Hz :D , and only slightly bigger than the old
firmware (though, with many fewer layers compiled in...) (also, the
winavr makefile gets the hex to be smaller somehow; i should probably
look into that)
fixed a comment, and made a few var names more consistent
(fixed a name, to go with the last commit)
now releasing keys on the same layer they were pressed

lol - i'd forgotten to do this before
fixed (or... worked around) a silly macro bug