Changed back to logout button.
Addressing Issue #72 and #76. Mission Ids are still to be swapped so that also the scoreboard visualizes in the correct order
Fixing Issue #74
Fixes issue #77.
Adds issue #73.
Improved profiletab.
Fixes issue #71.
Fixed mission1 constraint. Fixed GameEngine bug.
Browser icons added and small text change
Tutorial tab with screencast video added.
Merge branch 'dev' of https://github.com/dhennes/jupiter_tour into dev