evas cutouts - quickly avoid huge per issues with large nos of cutouts

evas cutouts - quickly avoid huge per issues with large nos of cutouts

i found evas_common_draw_context_apply_cutouts() was procsessing 300+
cutouts and as it's O(n^2)/2 to try and merge adjacent rects for
cutouts this really performs like complete junk. we apply cutout rects
a LOT. this is not the best solution, but it's quick and much faster
than doing the clipouts which drop framerate to like 1-2fps or so in the
nasty case i say (tyls -m of photos in a dir with a 2160 high
terminal).

this figures out the target area to limit the count of rects
significantly so O(n^2) is far far better when n is now < 10 most of
the time. and for the few operations where it's a high value this now
uses qsort to speed up merges etc. etc.

@optimize