Fix a bug of retinaParameters.
When colorMode is set to 0 via Retina::_init method, _retinaParameters's
colorMode variable is not correctly assigned.
Merge pull request #4 from Itseez/2.4

OpenCV changes
Fix bilateralFilter function
Make some tweaks to make `sum` operations less frequently
Fix build error.
Remove trailing whitespace.
rewrite gpu stereo multi gpu sample:

* use different approaches -> threads and streams
* clean up code
fixed building OpenCV with IPP 6.x (different DFT API); added Canny and rectangular morphology (based on Alex Kapustin patches)
fixed bugs in rectangular morphology case
Add IPP support in compare function
gpu -> ocl
enabled some tests that failed before OCL_TEST_CYCLE*() macroses were defined and for some tests was disabled SANITY_CHECK, because plain and ocl results must not be completely equal
Merge pull request #5 from Itseez/2.4

Some changes in OpenCV
Add IPP support in meanStdDev, minMaxIdx, norm functions
Merge pull request #1370 from ilya-lavrenov:ocl_decor
Merge pull request #1363 from ilya-lavrenov:ocl_enable_tests
Remove extraneous colon before ':basicstructures:'
Correct name of eye function
Merge pull request #1236 from pengx17:2.4_fix_retina_color_param
Merge pull request #1266 from kdrobnyh:core_stat_functions