Undo accidental patches to this file.
Undo accidental changes originating in a botched merge on Joey's branch.
Remove the free surface description. This piece needs to move to a different
branch and pull request.
Rename the directory for a plugin.
Reindent and minor edits. Properly declare that the viscosity depends on the temperature.
Go through the new section and edit and revise it. Make the input files in the doc/ directory only those pieces that really matter.
Adjust input files somewhat.
Properly break the list of contributors.