COLS should be type size_t

[Gurganus, Brant L]

Currently COLS is an int which can default to being signed or unsigned on different machines. As far as I can tell, though I don't have significant experience with ncurses, there shouldn't be a reason for these to be negative and since they are size of something, they should use size_t which, on most machines, should be unsigned. Ambiguity about its signed/unsigned nature can lead to problems in comparing signed and unsigned values. It should always be the case that anything you would compare COLS to would be a size_t so the signed/unsigned issue wouldn't come up.

Brant Gurganus
http://www.rose-hulman.edu/~gurganbl