work on formulations and sequence of start page
improved edit session screen

- usage hint
- highlight selected ascent
- remove ascent from list using trash icon
separated list-icon mixin from list-items mixin
updated text of feature preview pages in app
reordered columns in session list
moved demo login functionality to user service
enabled logins on start page again
link, strong, and header styling
styling and content of start page
added alpha to logo on start and added notify
work with Tony on start page
reenabled boulderwelt
removed unnecessary ng-switch
added photos of us to start page