Made changes in classifier`s files containing math.h include and replaced them with shogun/mathematics/Math.h as told in issue 1328.

There are other files too containing math.h which need to be replaced and on my pc i have done and compiled it already and its working fine. As this is the first time i am making a pull request i thought of committing only small changes. I will make all required changes in my next pull request.
ehm, what is going on here?