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
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
fixed wrong regex
1. Let btvRegWeights to be constant per `process` call.
2. Let Farneback to be the default optical flow method.
3. Fix a timing method bug for ocl path.
4. Remove useless finish operation in farneback
5. Refactor buffer usage.
regex doesnt need to match full length of input, so only trying to match the leading -[lL]
Add better OpenMP detection and make an option to enable it.

Bug report and inspiration: http://code.opencv.org/issues/3328
workaround for cv::multiply bug
moved to relative errors in ocl::norm tests
cmake: fix bug with installation into OPENCV_LIB_INSTALL_PATH directory
fixed an accuracy test for ocl::resize (in some cases dsize.area() was equal to 0)
fixed ocl::copyMakeBorder
ocl: show diff
Merge pull request #1669 from ilya-lavrenov:ocl_copyMakeBorder
Merge pull request #1672 from ilya-lavrenov:ocl_arithm
Merge pull request #1673 from ilya-lavrenov:ocl_norm
Merge pull request #1676 from ilya-lavrenov:ocl_resize_test
Removed incorrect release of obtained colorspace. This fixes bug #3318 (updated commit for 2.4 branch)