Rename ReleaseItem to ReleaseIndexItem
Add a level above the ReleaseIndexItem to map to the changes files
Remove UploadItem, it wasn't being used
Make control compatible with persistant storage
More tweaks to changes
Initial work updating changes struct to idiomatic object
Start breaking up changes processing a bit
Start breaking up changes processing a bit
Begin looking at processing of debs
Code reorg
Refactor around changes files.

Far too much in here.

- Refactor \core around changes files
- Create sources.gz from any uploaded dsc files
- Architecture is no longer relevant to pruning.
- Lone deb upload creates a changes file
- Make some of the json output a bit less verbose
- Remove some pointless interfaces (some remain)
- Rename validate to verify
Bounce changelog