Fix showing deleted items in recent view.
Use resource strings for notifications.

Use string values from android resources for displaying no description
and no project time entries in the notification.
Check for non-persisted time entries.

Make sure to not return a non-persisted time entry when looking for the
currently running time entry using TimeEntryModel.FindRunning().
Fix indent.
Refactor AndroidNotificationManager.

The notification manager did not update the notification when the
underlying model changed, it also sometimes could show the
deleted/non-persisted time entries as running.
Fix updating deleted time entry duration.

In case the time entry is deleted before it is stopped make sure we
don't update it's duration.
Merge branch 'roosmaa-zombies'

Closes #48.
Closes #45.