Add new ocl kernels for warpAffine and warpPerspective,
The average performance improvemnt is about 30%. The new
ocl kernels require CV_8UC1 format and support nearest
neighbor and bilinear interpolation.
Signed-off-by: Li Peng <peng.li@intel.com>

* restore Google Test 1.7.0 (get patch)

* ts: update Google Test to 1.8.0 release

https://github.com/google/googletest

* ts: re-apply OpenCV patch for gtest

* ts: fixes for gtest 1.8.0

* ts: workaround MSVS2015 problem in gtest

 ExifReader::getExif may enter infinite loop with jpeg image which have no EOI.
For example, bytesToSkip may be set to 0 and fseek seems like fseek(f, -2 , SEEK_CUR) for image that end with RST7(FF D7) instead of EOI.

Fix docs explaining the returnPoints argument of convexHull.

* fixed wrong equivalence in YUV conversion

* fixed channel order from YVU to YUV