Fix visualization output time

The visualization output still uses seconds rather than years even if
the “Use years in output instead of seconds” parameter is true, this
patch should fix it
Minor fixes to last patch
Merge remote-tracking branch 'upstream/master'
Add missing endline.
Merge pull request #6 from bangerth/master

Add a missing newline.
run astyle
Merge pull request #7 from tjhei/astyle

run astyle
Augment the documentation.
Merge pull request #8 from bangerth/master

Augment the documentation.
add another main goal in the documentation
Merge pull request #9 from tjhei/editmanual

add another main goal in the documentation
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