cv::Mat to CDenseFeature conversion Factory and vice versa.

I have made a factory which directly converts any cvMat object into any(required) type of CDenseFeatures. 
and  CDenseFeature<float64_t> into the required type of cvMat (any)
it would be cool do drop these cpp files as they have nothing interesting in them. I couldn't get it to work though when I removed this file and inlined the constructor, failed linking or something. @kislayabhi can you play around with this maybe @lisitsyn or @iglesias can help with why it failed to build shogun