Speedup about 30% on 6730M GPU.

1. Use macro defines for some parameters(radius).
2. Reduce local memory usage.
3. Fix accuracy problem on Intel GPU.

Add backwards portability for OpenCL 1.1 when OpenCV executables
are compiled with OpenCL 1.2 profile support.

A modification of the JavaCameraView is needed to avoid a crash when the
app is exited. It is a good practice to remove the callback after the
stopPreview method.

fixing precommit build on ubuntu-64 (now it takes OCL headers from non-default OCL SDK, but libs from default one)

This also fixes the bug where the Sphinx version gets detected as
"Sphinx vX.Y.Z" instead of "X.Y.Z" on Unix-like systems.

Also cv::, cv::gpu:: and cv::ocl:: namespace prefixes can be safely omitted
inside CV_ENUM and CV_FLAGS