Implementing + and - in terms of += and -=.
Implementing != in terms of ==.

OpenCV 3.0.0 Alpha

trying to solve compile problems; temporarily disabled some tests for just added optimization algo's

removed optim module; moved its functionality to core and photo modules; moved drawing functions from core to imgproc. Removed FilterEngine etc. from public API

Minimal image size is set to 5*5 for OCL path of fastNlMeansDenoising and fastNlMeansDenoisingColored since it breaks tests with test_loop_times=30 and in general doesn't make sense for computation on GPU.