Bug #1890 Opencv 2.4.0 with QT 4.7.4 and cvcreatebutton exception fixed.

QVector range check exception fixed.
Applied fix suggested in bug 3282 and shortened code
fix #3296 : Unsupported gpu architecture 'compute_21'
fixed cmd parser when arg is like -+
Added -l prefix to EXTRA_COMPONENTS when generating pkg-config file
changed foreach variable to match naming conventions and dropped intermediate variable, appending directly to the LIB_COMPONENTS list
refactored filters in the ocl module; added an accuracy tests for ocl::medianFilter
ocl: perf: use RELATIVE_ERROR in SANITY_CHECK for exp/log/pow
fix imshow under Windows with OpenGL support:

we doesn't create OpenGL windows by default
OpenGL window must be created by user via namedWindow
Only append -l to lib entries with no path and no -l or -L of their own
shortened code to not repeat myself
added backslash
cmake: cleanup OpenCVModules_TARGETS from cache

This will allow to disable modules between cmake runs
Updated ffmpeg_vesion.cmake after #1516.
Merge pull request #1626 from ilya-lavrenov:ocl_filters
Merge pull request #1640 from alalek:ocl_fix_exp_test
added Khronos OpenCL 1.2 header files
ocl: force to use Khronos OpenCL headers
ocl: update autogenerated code
refactored all the tests in ocl/test/test_imgproc.cpp