- Handle resource URIs in the WV Client

- Switch from URI to Uri in the WV Client
- Canonicalize resource URIs if necessary
- Switch from HashMap to SharedPrefs in CacheProvider
- Use cache when going forward too
- CacheProvider remove old entries in onCreate()
- CacheProvider cleanup
- gc on router stop
- Add reload menu item
- Don't return to welcome page on activity restart
- Notification on client tunnels up/down