Adding first gitignore file. Probably needs some more file types.
Implementing first draft of VSI files that behave pythonic-file-like.
Copied tracs component system.
Adding first draft of backend component.
Adding new interface types for backends. Replacing admin choices with dynamic choices from plugin components.
Fixing castable to use cached content type lookup. Implemented draft of plugin initialization.
Renamed '_remove' and '_insert' with 'perform_removal' and 'perform_insertion'. Removed unused model admin inlines. Added additional tests.