Added option to get the solution from the previous iteration instead of the current iteration.
Update loadInputDeck() to allow material property vectors to be filled in if not the right size.

You can now specify just one value for something like sigma_s0, and it will assume that the entire domain has that value, even if the domain is not homogeneous.
Also, the warning about using diffusionSolve() for multi-region problems is reworded to be more clear as to where the warning is coming from.
Modified declaration to use 1.e-16 instead of 1e-16 for default value.
Fix Qhat definition for reflective boundary, improve convergence criterion.

Qhat_edge is now set to 0 for a reflective boundary, which is correct since the 1st moment is trivially satisfied at all times for a reflective boundary.  No Qhat correction is needed.
Convergence criterion is now improved so that very small Qhat values (on the order of the tol) are ignored.
Modify convergence criterion for Qhats so that their relative change is compared to norm of phi_0.  Add error history vector.