TODO: Refresh summary when a setting is changed.

The navigation drawer has been (mostly) migrated to link to Activities instead
of Fragments. Only Activities can be searched via the inbuild Android search
function, which uses Intents.

The SeekBarPreference class needs fixing to follow resource references.

- Update release notes
- Lower log levels
- Spelling fixes on settings page

Added AddressbookSettingsActivity, and a link via settings. It's now possible to update subscriptions.txt on android.

- Catch loadUrl() exception
- Stub out settings and menus
- Enable double-tap to zoom in webview on Droid