(cherry picked from commit 8910508b)

The current link does no longer seem to work.

it tries to remove 'opencv_' prefix from 'name' variable, but
it creates new variable with the same name as module

- Previous version just checked option support, but not enable it.
- Also OpenCV tests reports invalid AVX and AVX2 support status.

Get rid of cvconfig.h in Latent SVM samples. Use common OpenCV parallel framework instead of direct TBB calls.

"int * CvMLData::sample_idx" was not freed