VideoCapture didn't call release method and just ignored the new capture sources.
OpenCV documentation:
  bool VideoCapture::open(const string& filename);
  bool VideoCapture::open(int device);

The methods first call VideoCapture::release() to close the already opened file or camera.

Also, shrunk the corresponding column and the test name column.

- set init value for `numsdev` to prevent use of uninitialized value
- stop use of 'workdir' and files from samples
- forcing use of 'opencv_extra' instead
Note: set OPENCV_TEST_DATA_PATH to full path to 'opencv_extra/testdata' (gitolite@code.opencv.org:opencv_extra.git) before running the test!

Downgrade TBB to 4.1u2 for all platforms, except WinRT.

Fixed issue 3130 (http://code.opencv.org/issues/3130), where one argument of the BRISK-call was ignored. Previously it was not possible to use BRISK without creating descriptors.
Now it behaves like ORB (and how it is documented), and you can call BRISK to just generate feature points and no descriptors.