Patch by Jacqueline Austermann: Update the dynamic topography postprocessors.
Fix a number of text issues.
Run astyle on the new files.
Rename a member variable to conform to common style. Fix a text issue.
Add a new test.
Run only a single time step.
Add the correct output files for this test.
Document changes.
Merge pull request #22 from bangerth/new-dynamic-topography

Changes by Jacqueline Austermann: Implement an improved postprocessor for the dynamic topography, taking into account the dynamic pressure.