Let ocl::filter2D support kernel size >= 3.
Update with apavlenko's suggestions.
bug #3094: added CV_Assert to PyrDown_ to check if source matrix is not empty
Fix for bug Bug #3215. Added HAVE_QTKIT as a separate mode from HAVE_QUICKTIME
added HAVE_QTKIT to tests
missed # in if defined
Merge pull request #1254 from pengx17:2.4_filter2d_
Fixed mismatching allocation and deallocation: el_ptr
bug #1922: restored most of the class definitions in basic_structures.rst
Merge pull request #1270 from rdm12:bugfix_3094
Merge pull request #1272 from kamjagin:fixingQTKitPublic2.4
Merge pull request #1276 from nghiaho12:mushroom
applied comments after review
Merge pull request #1275 from rdm12:bug_1922