it is a new 'feature' introduced by Telenav (Just in case you are wondering, the telenav upgrade is not part of the GB update - but the auto-restarting 'feature' seems to have been introduced with GB).
You can't unless you are rooted. Telenav is just an update and renamed version of Sprint Navigation. It constantly runs in the background if you are using it or not. That's why I keep it uninstalled until I need it then I restore it with titanium when I need it. Only can do that if you are rooted thin