Inference: fix fonts for Version label and About, Video screens.  We now use a sans-serif font everywhere.  This also seems to have fixed a bug where the bold word "Inference" was not displayed in the About window, for some reason.
Merge branch 'serg-TP-data-games/master'
Deleted old classes and removed references to them from remaining classes. Moved back/levels button handler to InterenceGames.mxml
Merge branch 'master' of github.com:serg-srri-umass/TP-data-games