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.

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

It is already marked as a gtest 1.7.0

Merge branch '2.4_ocl_bfmatcher_newtype' of https://github.com/pengx17/opencv into 2.4_ocl_bfmatcher_newtype

RadiusMatch for HammingDist cannot pass yet.