3.0 beta

I'm very thankfull for you work,but there is a problem,I chect it for many times,and I found it was not my cause by myself,In the doc,opencv_tutorials.pdf,page 414,the example programe used founction createBackgoundSubtractorMOG to create a model for GMM,but createBackgoundSubtractorMOG  counld never be found anywhere,it's head file supposed to be at opencv\bulid\opencv2\video\background_segm.hpp,but it doesn't have it,So,I think it might be your mistake to ignore the founction,and I think it is a very big bug,so I recomand you to recorrect it !thiank you!!!