The images for group avatars are stored directly in the datbase, which
is fine since they are small. But then there's no reason to have them
lingering on the filesystem.
Also removed the unused group associatedAttachmentId property.
// FREEBIE
What we *previously* refered to as attachments are actually just the
attachment's id (NSString). This has tripped me up a few too many
times.
Also, use generics with attachment id's array.
// FREEBIE
In theory, this should have already been handled by the
YapDatabaseRelationship extension via edges.
However, in practice, there were situations (cause unknown) where
interactions would exist without an edge to their corresponding thread.
Rather than being clever with the edge/callback machinery, now threads
explicitly delete all their interactions, and interactions delete all
their attachments (when applicable).
Also, a class to clean up spurious interactions / attachments
In the process:
- refactored TSYapDatabaseObject init to specify designated initializer
- added some testing niceties to TSYapDatabaseObject
// FREEBIE
