Added an implementation of manifold sculpting DR method (see ...

http://axon.cs.byu.edu/papers/gashler2011smc.pdf);
Added a method in tapkee library for converting FeatureCallback into a DenseMatrix (it was used previously a few times); 
refactored a little; 
added all the stuff needed for the new method to be 'visible' from outside the tapkee (according to https://github.com/shogun-toolbox/shogun/issues/1025).