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

I think this code with additional array `pb` is too sophisticated. May be you can merge this `if .. elseif ...` and two `if` above into something like:
```
bool check = true;
if (dir.x != 0)
{
    float temp = p0.y - p0.x * dir.y / dir.x;
    if (0 <= temp && temp < src_rows)
    {
        p0.x = 0;
        p0.x = temp;
        if (dir.x < 0)
            dir = -dir;
        check = false;
    }
    else 
    {
        temp = p0.y + (src_cols - 1 - p0.x) * dir.y / dir.x;
        if (0 <= temp && temp < src_rows)
        {
            p0.x = src_cols - 1;
            p0.y = temp;
            if (dir.x > 0)
                dir = -dir; 
            check = false;
        }
    }
}

if (check && (dir.y != 0))
{
    ...
}
```
Or this way lead to decreasing of performance?