add kmeans
Bugfix for an overlapping size of image and template for matchTemplate.

Example: img of size 10x10 and templ of size 11x9.
In subsequent code this will results in either width or height of
corrSize to be zero (0).
Line 261 will call crossCorr which will then have a zero size of either
blocksize.width or blocksize.height resulting in a division by zero
crach in lines 137 or 138.
remove the redundant function
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.
fix the function name
Fix ocl gftt file name typo.
xls-report.py: add ability to specify arbitrary sheet properties
xls-report.py: removed image size and type from the list of other parameters.

Also, shrunk the corresponding column and the test name column.
Added to the test log parser a crude ability to detect non-implemented tests.
Made the crude ability less crude.
xls-report.py: Added an option to show per-pixel times
Merge pull request #1080 from hhofbaue:matchTemplate_bugfix
Merge pull request #1088 from apacha:brisk_noDescriptors_fix
Merge pull request #1077 from bitwangyaoyao:2.4_kmeans
Merge pull request #1102 from SpecLad:xls-updates
Merge pull request #1106 from pengx17:2.4_gftt_rename
Fixed VideoCapture::open() does not release previous capture sources (Bug #3150).

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.