Prevents NPEs due to null instructions
Set BaseActivity launch mode to singleTask
Fixes spelling of NotificationBroadcastReceiver
Add some NPE protection to RouteFragment and RouteAdapter
Handle exit navigation intent via onNewIntent()
Removes unused field
Removes unused import
Pops fragments in onPostResume() to avoid IllegalStateException

http://www.androiddesignpatterns.com/2013/08/fragment-transaction-commit-state-loss.html
Merge pull request #290 from mapzen/chuck/preserve-routing

Resume routing from launcher icon and exit navigation from notification...