PRICE - image filtering and manipulation Code

change Copy&Paste not to use hard-coded TIFF representation, but in paste handle dynamically the types Image handles, on copy, offer also PNG if available. To handle that, callback provideDataForType has been implemented

update (c) year

status field shall be non-editable

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