Cherry-picked mariusmuja/flann@b615f2694723fe402b8bbe50d77e622beff7f171.

Original author: Alex Wilson.
fixed ocl::bitwise_not in case of CV_8UC1, CV_8UC2
Cherry-picked mariusmuja/flann@8c8b0e0cb879666797ab2ac51b9ee438bf84a183.

Original author: me.
Merge pull request #1547 from SpecLad:gtest-1.7
enabled ocl::norm perf test
ocl: dynamic load of OpenCL libraries

Support functions from OpenCL 1.1 / OpenCL 1.2
ocl: cl_runtime: added autogenerated code
Merge pull request #1550 from SpecLad:flann-uninit-master
Merge pull request #1548 from ilya-lavrenov:ocl_bitwise_not
Merge pull request #1549 from ilya-lavrenov:ocl_perf_norm
Merge pull request #1543 from SpecLad:name-enum
removed invalid comment
Merge pull request #1542 from alalek:cl_runtime
Merge pull request #1507 from pengx17:2.4_fix_test
After commit c7bbd1a, 'include_directories()' is needed in the CMakeLists.txt (user side). This commit updates the documentation.
Fixed VIZ compilation module (Bug 3297: code.opencv.org/issues/3297)
fix #3296 : Unsupported gpu architecture 'compute_21'
fixed convertC3C4 and convertC4C3 functions in case cols == 1
Android NDK r9 support. x64 NDK support fix for MacOS X.
Android NDK r9 support. x64 NDK support fix for MacOS X.