http://code.opencv.org/issues/2206,
http://code.opencv.org/issues/2924

extended MinProblemSolver::Function to 1) report the space dimensionality, 2) compute gradient if needed

fixed bug with simplex initialization in Downhill solver (thanks to Toby Rule for the patch): http://code.opencv.org/issues/3990.
re-enabled Downhill solver test, let's see how it goes

fixed http://code.opencv.org/issues/3935
possibly fixed http://code.opencv.org/issues/3594

fixed invalid output of cv::dft when using DFT_ROWS + DFT_COMPLEX_OUTPUT (http://code.opencv.org/issues/3428)

Conflicts:
	modules/gpu/perf/perf_imgproc.cpp

Cast a long integer to double explicitly.

Conflicts:
	modules/python/src2/cv2.cpp

Cast some matrix sizes to type int.

Change some vector mask types to unsigned.

Conflicts:
	modules/core/src/arithm.cpp

use CV_CUDA_TEST_MAIN for opencv_test_core to initialize CUDA
device information

it allows to use cudaHostAlloc methods for cv::Mat objects

fixed my_umat(roi).clone() test by disabling poorly aligned ROI's. Real fix of the problem will require a separate branch in UMat::copyTo().

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

Fix error in minmaxloc.cl
Change test for convertScaleAbs
Fix minMaxIdx for _src2 align
Change epsilon on the tests

1. someMatrix.data -> someMatrix.prt()
2. someMatrix.data + someMatrix.step * lineIndex -> someMatrix.ptr( lineIndex )
3. (SomeType*) someMatrix.data -> someMatrix.ptr<SomeType>()
4. someMatrix.data -> !someMatrix.empty() ( or !someMatrix.data -> someMatrix.empty() ) in logical expressions

Fixed buffer initialization in reduce kernel. Enabled OCL version of reduce for SUM, MAX, MIN modes.