added a new method to assign matrix values, which also avoids a (potentialy costly) initialization of the matrix sparsity.
shorter, better code that is shared among the classes. bug fix in zerorow, greater robustness in compression/uncompression of the sparse matrix.
added a working, extremely innefficient dlib-based solver (could be better, but what the heck.
works and looks better now (win-win).
works, looks better and is even simpler now (win-win-win).
improved the working of options, though i cant stop it from calling exit when a singular matrix is found. call Intel, not me.
looks better, but is not any better than before.
conforming changes to base class (neither solver is working at all yet_.