fixed extrapolation for ocl::cornerMinEigenVal and ocl::cornerHarris; enabled CV_32FC1 for the first function

It supports NORM_L1 distance types now and can
use user provided indices.
Also fixed a bug of kmeans where distance pointers should be float instead
 of double.

NORM_L2 changed to NORM_L2SQR, Accuracy and Perf tests are added

added ROI support in accuracy test of distanceToCenters

Reordering condition checking.

1. HaarDetetctor: repack nodes to reduce memory footprint
2. cornerMinEigVal: 4 ocl kernels are fused into 1 for sobel calculation