OCL: HoughLines and HoughLinesP

Added OCL version of HoughLines and HoughLinesP to T-API, based on CUDA implementation.
Merge after Itseez/opencv#3278.

**Performance report**
http://ocl.itseez.com/intel/export/perf/pr/3279/report/

check_regression=*OCL*HoughLines*
test_filter=*OCL*HoughLines* 
test_modules=imgproc
build_examples=OFF

Why do you need new variable `p1`?