Show notification (with progress bar/file names) when syncing

[smihael]

It'd be nice to have an option to see when and which files are synced. On desktop you can see this in system tray, on Android an elegant way to do so would be with notifications.

In the settings, it would also be nice to be able to control sync intervals.

[scubajeff]

Sync status can be checked in Setting, has progressbar and filename, etc. shown.

As for sync interval, it's fixed at 6 hours. Besides that, whenever you open Les Pas, it will sync once.