styling enhancements
remove end button from activity view, when not tracking
enhance styling of tracking_end button when hovering
slightly enhance styling of signup form
emit "duration_change" event also on change of start/end
add startup check for browser requirements
remove nvd3.css since this is not implemented yet
cleanup index.html
add roadmap draft
add basic timeplan to roadmap and extend features
update bitbucket url
corrent startup command
slightly refactor user.login
add groupLabel as id attribute