* face module now links to calib3d instead of video module

replace to CV_Assert_N()

 modules/stereo/src/descriptor.cpp:229:34: error: ordered comparison between pointer and zero ('const int *' and 'int')
	     CV_Assert(image.size > 0);
		       ~~~~~~~~~~ ^ ~
 modules/core/include/opencv2/core/base.hpp:478:84: note: expanded from macro 'CV_Assert'
 #define CV_Assert(...) do { CVAUX_CONCAT(CV_Assert_, CV_VA_NUM_ARGS(__VA_ARGS__)) (__VA_ARGS__); } while(0)
										    ^~~~~~~~~~~
 modules/core/include/opencv2/core/base.hpp:455:35: note: expanded from macro 'CV_Assert_1'
 #define CV_Assert_1( expr ) if(!!(expr)) ; else cv::error( cv::Error::StsAssert, #expr, CV_Func, __FILE__, __LINE__ )
				   ^~~~
 modules/stereo/src/descriptor.cpp:230:33: error: ordered comparison between pointer and zero ('const int *' and 'int')
	     CV_Assert(cost.size > 0);
		       ~~~~~~~~~ ^ ~
 modules/core/include/opencv2/core/base.hpp:478:84: note: expanded from macro 'CV_Assert'
 #define CV_Assert(...) do { CVAUX_CONCAT(CV_Assert_, CV_VA_NUM_ARGS(__VA_ARGS__)) (__VA_ARGS__); } while(0)
										    ^~~~~~~~~~~
 modules/core/include/opencv2/core/base.hpp:455:35: note: expanded from macro 'CV_Assert_1'
 #define CV_Assert_1( expr ) if(!!(expr)) ; else cv::error( cv::Error::StsAssert, #expr, CV_Func, __FILE__, __LINE__ )
				   ^~~~

* Process InputOutputArray when BM3D_STEPALL is set

* Step1 created if needed- noArray in test

Adds Edge-Preserving Filter (#1690)

* Module EPF - Edge-Preserving Filter added

* Changed name from template to epf

* Removed clang-format file

* Added header Files. Eliminated showWindow function. Used CommandLineParser.

* Moved filter from epf module to ximgproc

* Removed header files from sample

* Minor bug fix in demo. Pointers in demo removed.

* Pointers removed. InputArray/OutputArray added

* License header added

* License header from sample file removed

* Unit test for performance added

* Replaced manual mean computation with cv::mean

* Beautified code via clang-format and https://raw.githubusercontent.com/opencv/opencv_contrib/master/modules/cvv/.clang-format

* Merged historic if... else if statement into one if statement

* Trailing whitespace removed and .. changed into .

* Tabs replaced with 4 spaces.

* Removed subwindow = src(roi);

* Moved type test to beginning of code

* Removed indentation from namespace and added //! @}

* Added name to header

* git cleanup introduced some errors fixed here

* Changed path testdata/perf/320x260.png to perf/320x260.png

* Fixed warning declaration of 'subwindow1' hides previous local declaration

* Fixed warning 'const' qualifier on reference type 'cv::InputArray' (aka 'const cv::_InputArray &') has no effect

* Accuracy test added/

* Renamed void edgepreservingFilter to void edgePreservingFilter