Allow multiple syncs per day, sync regardless of day

[emsariel]

Store a timestamp for when the sync was (successfully) run, or otherwise mark tasks in OF.

When the script runs on OF's history, it then processes all tasks since its last sync, rather than the full calendar day/yesterday.

Original issue from wiki: Working towards a system that syncs / marks tasks in OF to allow for the script to be triggered multiple times per day and catch all task since last trigger.

[matthewspear]

A simpler approach may be possible based off last sync date and a count of the number of completed tasks since that date. This would save having to mark tasks and avoid the complexity of interactive with a log.

[emsariel]

Aye. Marking tasks in OF seems ... hard. The general approach of: find the tasks since the last sync date (either count or just the list), then iterate through them ... seems like the way to go.