Split into separate modules

[christianbundy]

Currently this module does three things:

• deletes content from flumelog-offset
• deletes Scuttlebutt feeds (which use flumelog-offset)
• deletes Scuttlebutt flume views

I think this should probably be at least two modules:

• flumelog-offset-delete
• ssb-db-delete

Maybe? There may be a better way to go about this, but I wanted to document my current thinking on this.

[christianbundy]

Here's my attempt at an exhaustive list of all possible modules in this space:

• flumelog-offset-delete: deletes content from an instance of flumelog-offset
• ssb-delete-feeds: uses flumelog-offset-delete to delete a list of feeds
• ssb-delete-blocked: uses ssb-delete-feeds to delete all blocked feeds
• ssb-delete-flume-views: auto-deletes all flume views in ~/.ssb/flume/
• ssb-blob-prune: remove all unused blobs
• ssb-delete-cli: a single CLI that does all of the above would be sweet (maybe an sbot plugin?)