Say 'mod' instead of '5' on users per trust level table
Fix admin dashboard layout on smaller widths
Move a bunch of callbacks into PostCreator
Username change: check length in js, we don't need the server to do it
Move MessageBus observer into PostCreator
Converted flag threshold constants to enums
Move draft sequence incrementing out of `after_save`
Moved more `Post` callbacks into service classes
Convert Post type constants to Enum
PostDestroyer to replace callbacks for destroying