* Adding Nalu package.
* Fixing flake8 stuff.
* Fixing flake8 stuff.
* Reorganizing trilinos package file a little to make it less verbose.
* Reorganizing trilinos package file for more general use as well as use as a dependency of the Nalu package. Setting fpic as default for yaml-cpp and superlu.
* Explicitly stating fpic variants in dependent packages.
* Updating nalu and trilinos package files with suggested changes.
* Fixing formatting issues. Making suggested changes.
* Fixing formatting.
* Reducing amount of explicit variants in Nalu. Adding suggested changes to Trilinos package file.
* Making suggested changes to Nalu package.
* Turning off superlu-dist variant.
* Cleaning up yaml-cpp file.
* Fixing pnetcdf requirements in trilinos.