stateio: file management for exports/imports

[ghukill]

Consider including the following methods and capabilities:

• ability to delete import/export on disk, likely saved as export_path in proposed StateIO model
• automatically compress on export
  • one example resulted in 1.3gb --> 95mb, so quite significant
• decompress and unzip on import

[ghukill]

Mostly complete:

• compress on export to
• decompress on import
• establishes import_id, much like export_id, that can be used to track files

[ghukill]

Need, still, to handle uploading imports. Removal of export's export_path is built into signaled pre_delete().

Imports will have two locations:

1. export archive is uploaded, saved to state.export_path
2. export is unzipped, this location is state.import_path

On removal, both will need to be removed. But, likely makes sense to remove import.export_path post decompressing.

If directory passed from filesystem, should flag be set such that removal of import state will not delete from disk?

[ghukill]

Done.