Add OpenCL version 1.2 query into ocl::Context::supportsFeature().
Add backwards portability for OpenCL 1.1 when OpenCV executables
are compiled with OpenCL 1.2 profile support.
ocl: Enable backward binary portability for setTo function.
Suppress warning when compiling deprecated OpenCL function on GNU compilers.
Merge pull request #865 from pengx17:2.4_ocl_ver