Merge pull request #81 from luhcas/master

Darstellungsfehler in Navigation behoben
transfer CSS changes from fb77c34 to LESS
make Sections editable and add tooltips
explicitly declade deferred in edit_view
add section's title to HTML
fix coding style
extract section's title partial
add editing of sections
rename methods in section JS
move Courseware#reload to helpers
remove vips-navigation, fixes #75
Optische Anpassungen des Tooltips und Navigation