Replacing math.h with shogun/mathematics/Math.h.

According to issue 1328 i have made changes in only 2 files so that changes can be reviewed properly also i will push changes in other files in this branch subsequently.
I've just quickly browsed through this header file and I don't quite see why this include is needed at all (maybe I missed anything, though). Could you try to remove the include here? You may need to include it in the cpp file in case it is used in there.

Also, I think the includes for limits.h and SGIO are not needed here either.