filesync-style operation

The default should be that other tools integrate with OI directly to upload at the right time (example ctengel/pervellam#17 and ctengel/linkmeddle#67 ); however, sometimes there is a need to back up stuff where we can't or haven't gotten to modify in this way, where the tool is still posix-fs native.

This is where the beauty of filesync comes in as it doesn't place any requirements on what the downloader must do.

Therefore, we should create an OI client that leverages filesync functionality or even code to scan for files ready to sync and upload and delete originals as filesync does. This would then largely supplant ctengel/filesync#4 and perhaps filesync itself.