Add IPP erosion and dilation
Add sort_by_key for oclMat.
Most codes are ported from AMD's Bolt library.
Four methods are implemented:

SORT_BITONIC,   // only support power-of-2 buffer size
SORT_SELECTION, // cannot sort duplicate keys
SORT_MERGE,
SORT_RADIX      // only support signed int/float keys
gabor filter docs Bug#1894
ref in inpainting docs
pydocs for cv2.findTransformECC
Removed CV_EXPORTS from all template classes (that I could find).

It doesn't make sense to export template classes, since there's no way
the user can learn that it can import them. In fact, it is somewhat
deleterious, because every module will export every instantiation
that it uses, but doesn't inline.
Add IPP mean and sum functions
Fix build errors
epilines pydocs
Some changes in sum and mean functions
morphologyex docs bug#2169
imshow docs improvement bug#2490
Some modifications to sortByKey API.
Add documentation.
Fix doc build error.
Some changes in erosion and dilation 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.
disabled 64f IPP DFT; added IPP Gaussian filter; added IPP GetRectSubPix; added IPP BilateralFilter (temporarily disabled)