la4j new feature

Hi!

I was working on my educational project, and used la4j for some routine (Matrix and Vectors initialization, multiplying etc.)

I needed to solve system of linear equations, but surprisingly it was degenerate. I used SMART solver, but I got huge problem - some variables in result were near infinity. 

So, I decided to implement one of approximate algorithms - for this purpose I took Nonlinear Conjugate Gradient method. 

Now, I suggest you to take a look at this pull request. Here it is new package in la4j, org.la4j.opimization, which is designed same as org,la4j,linear.  But with this type of solver user can find approximate solution with some accuracy, if it is possible. The bonus is that user can also search for solution for standard equation Ax=b, even if number of variables is greater then equations. I used this solver for 45x70 matrix, and got pretty good result.

Waiting for your response.

Regards,

Iurii Drozd.