Support for Compressed Files, leftover of #3.

[vjeeva]

This can involve multiple things: One would be that the path up to the compressed file must have the most specific date, multiple dates/times in a zip will not be supported as analysis cannot be made statically about the backups available, their timestamps and what needs to be run. What this means is the zip must be one per timestamp, and all files in it should all be run as part of that timestamp.

[vjeeva]

This would be interesting because zips I think are used for mongodb backups, one per backup. However if we let users zip up multiple like sql files in a timestamp zip (eg for multiple databases backed up at the same time), that makes it more complicated too.

If we limit a config per db, that could be better, but also may not scale well. If we allow people to lump their backups into a zip per timestamp, we'd have to distinguish if the zip is for multiple backups or a single one (mongo) for dispatching. This can stretch into mongo having nested zips too.