Huge block of files that I should have commited before but didn't.  These are the temprary libraries that will hold the Object Oriented version of PeYeQM.

Classes.py contains definition of the classes that are needed to set up a simulation. This is:
 + Simulation
        + Domain
              + Elements
                  +triangles
              + Nodes
 And such. Interpreter contains clases that are used to build the corresponding set of linear equations to the simulation defined before.

I will start commiting more often now that the OOP version has been uploaded.