message: Hide info section if there is no info or you are not the owner
diff: time( datetime= block.get('updated_at'), title= block.get('updated_at') )
  | Last updated #{block.updatedAtAgo()}
  +
  + //- Possibly hide entire info section
  + if (user && user.id === block.get('user').id) || block.get('description') || block.has('source') || block.has('image')
  section.BlockSidebar__section
  header.BlockSidebar__header
  | Info
  != block.get('description') || '&nbsp;'
  .BlockSidebar__provenance
  - if block && (block.has('source') || block.has('image'))
  + if block.has('source') || block.has('image')
  a( href= block.getSourceUrl() target='_blank' )
  span= block.sourceTitle()
  