Fix forgotten resizing of depth average files. Add an assertion.
Merge pull request #10 from bangerth/fixes

Fix forgotten resizing of depth average files. Add an assertion.
Style fixes.
More style fixes.
Simplify some code. More style fixes.
Style fixes.
More style and documentation fixes.
Merge pull request #11 from bangerth/fixes

Style and documentation fixes
fix .gitignore
Merge branch 'master' into direct_solver
simplify base_element logic
introduce parameter for direct solver, some cleanup