ODE code and tensor product

[mdumett]

The following examples are basically implementations of ODE integrators and a tensor product which do not solve a PDE: KG_product, RK2, RK4, backward_Euler, van_der_pol. In the best case scenario they should be relocated as a utility but it seems to me these are pretty simple algorithms that should not be among the examples. An option may be removing them.

[jbrzensk]

This is a throwback to when the library was used with the COMP 670 class, and these were examples for students to use to implement time integration schemes. I think they should stay for people to use for their own examples.

[jcastillo001]

If we keep them, they should be on a space called "Utilities/Time Intregration Schemes

[mdumett]

I agree with the idea of having under utilities in a special subdirectory.