clean up of html elements, added containers
added some basic css styles
changed base font-size to fixed pixels
adjusted display of "logo"
added responsive behaviour for login dialog
added logo, optimized layout
basic rework of session overview
added normalize.css
reorganized css, added session overview with responsive table
readded logout link/button
added box css class
moved table css definition to top
added logout dialog
use translations for all strings
changed global font style
made buttons look a little better
added footer
optimized responsive behaviour
footer is now a partial and shown on all pages
show errors in login window