Merge pull request #223 from adamarla/master

Fixed issue with refreshing
preview_images hack -> Show pngs for quizzes with ID > 751 ...

The Makefiles changed and hereonafter PNGs are generated
Merge branch 'master' of github.com:abhinavc/web-application
 removed hack in preview_images
superwide panel can be span12
update app signature on each refresh
Merge remote-tracking branch 'upstream/master'