Show version of augmentations.
Allow the user to delete augmentations.

There are now two kinds of augmentations: Resource augmentations (those
loaded from SeeC's shared resources directory) and UserLocal
augmentations (those loaded from the user's local data directory). Only
UserLocal augmentations may be deleted through this interface.
Use only the most recent version of augmentations.

If there are multiple augmentation documents with the same ID, then only
use the document with the highest version when performing augmentation.
The unused augmentations are indicated by greyed (disabled) text in the
augmentations preference panel, but can still be interacted with
(deleted). If an active augmentation is deleted then it's automatically
replaced by the most recent version (if any). Similarly, if a newer
version of an augmentation is downloaded it automatically replaces the
existing version.