PRICE - image filtering and manipulation Code

fix includes

update datePRWindowController.m

improve paste behaviour

do not scale if we have no sender

some better checks, asserts and minor fixes

Make changing channels in RGB correctly set the current black and white point

draw curves and histogram in a preferred order so that the selected one is always on top

size exactly 255x255

make view exactly 255 px wide and hight, make the view resizable

use max normal size for calculation, transformation is applied later, the size is not important anymore