Replace Profiler with Debugbar
Update trigger on relationship_revisions so it updates updated_at on relationships
Add sorting to relationship list

- Relationships list changed from list to table, with sortable column
  headers
- Items per page can now be changed by the user
Comment on Relationships instead of RelationshipRevisions

- Makes it easier to count comments on any given Relationship
Update insert triggers to use timestamp of created row, to avoid
timezone mismatch
Update 'down for maintenance' message
Show icon next to relationships with comments