Start with LU solving - just to debug algorithm

Signed-off-by: Tony G <mipt.shootnick.spam@gmail.com>
Simplex solving v1 + optimization to n^2 complexity

Signed-off-by: Tony G <mipt.shootnick.spam@gmail.com>
Add tests. Improve algo.

Signed-off-by: Tony G <mipt.shootnick.spam@gmail.com>