Add IPP mean and sum functions
Some changes in sum and mean functions
Update OpenCVDetectPython.cmake

On my MacOS the output of the sphinx-build binary is the following:

Error: Insufficient arguments.

Sphinx v1.2b1
Usage: /usr/local/bin/sphinx-build [options] sourcedir outdir [filenames...]

...

I have installed sphinx, but without this change HAVE_SPHINX==0 for me, so I can't build docs.
Removed useless .*
Merge pull request #1216 from alekcac:sphinx
Make ts always static.

This allows us to forget about the GTEST_(CREATE|LINKED_AS)_SHARED_LIBRARY
macros and to get rid of the dependency on cvconfig.h.
Merge pull request #1231 from SpecLad:static-ts
Merge pull request #1187 from kdrobnyh:mean_and_sum
Merge branch '2.4' of https://github.com/palindromoroz/opencv.git into bgfg_KNN_new_code

Conflicts:
	modules/ts/include/opencv2/ts.hpp