More 0.4.0 release prep

A little house keeping before the 0.4.0 release. Mainly shutting up warnings from the compiler. Note I'm merging into the 0.4.0-release branch of grinsfem/grins. The 0.4.0-released is brached from where the new gold standards were put in for the regression tests and before some of Vikram's initial work was merged in (mostly because that will be more logically connected with what's coming down the pipe so why separate it into two different releases).

I believe I just need to update the CHANGES file now. I'll wait to merge until I push a commit here that updates the changes file.

Otherwise, make distcheck is passing for me. I think after this is merged, we can tag 0.4.0 from the end of the 0.4.0-release branch and merge it back into master.

Any objections?