NEW:
  Performance improvements.
  - Handling cover images is faster and the UI should be snappier
  - Internal loops have been removed/improved.
  While some of the above will show, other parts may be subjective

FIXES:
 #199: image deletes no longer cause UI pauses
 #200: fallout from #193: duplicate authors (and more) were generated
       This fixes duplication and cleans up existing duplicates
 #202: author aliases can be removed
 #205: BC imports ignore the "read=0" flag if a "red_end" is set
