Bounds Vectors

[friedmud]

Dmitry needs two solution vector sized vectors for SNESVI. One for the lower bound and one for the upper bound. He also needs a way to fill them with the information.

[friedmud]

Because this whole idea is still in flux I'm going to do a quick implementation that relies on the Auxiliary Kernel system. The idea is to make a nodal aux kernel that, instead of filling in it's own solution vector, it will fill in the lower and upper bound vectors for the variable we tell it.

To tell it the right variable we're going to use the coupling system. This will give us access access to that variable's dofs on that node. Note that this whole thing will only work for Lagrange variables... but that's ok because this is just a testing system.

As for actually adding the vectors, I'm going to add a new main block called [Bounds] with an action associated with it that adds the bounds vectors at the right moment.

[friedmud]

In 72ae577:

add initial implementation allowing specification of bounds on a variable references #951

[friedmud]

Marking this as fixed... we'll open another ticket if we need something more.