[FF] Classifieds Enhancements (+ Fixes) 1.1.9

A few useful extensions for NixFifty's Classifieds system - as well as any bug fixes that I spotted.

• Require prefix
  Adds a new option in the category edit page to require a prefix for posted items.
  
  
• Linked prefixes
  Link a classifieds prefix to a thread prefix - so the created thread can use the classifieds prefix, rather than just the category.
  
  
• Prefix filter under category
  List all the prefixes under each category in the navigation block that have items assigned.
  
  
  
  (Fiesta and Puma are prefixes, not categories)
• Customize thread title
  If you have enabled the create thread when item posted option, you can now customize the title.
  
  
• Allow moderator to mark item as sold
  
  
  
  Enable a moderator with the "Clear sold status on listings" permission can now also use the "Mark Sold" button.
• Allow user to renew expired listing
  Adds a new "Renew listing" button on the action bar. Will show up for the listing owner, as well as a moderator with the ""Edit any listing" permission.
  
  
• New Widget "[FF] Classifieds Enhancements: Listing Filter"
  Display the filter drop down as a widget instead.
• FIX: Carousel image display
  Correctly show the right number of items in the carousel (2 on mobile, 3 on everything else)
  
  
• FIX: Carousel navigation dots
  See above image.
• FIX: Price input as number instead of text
  Solves the issue with people entering "," as a thousand separator
  
  
• FIX: Widen the left hand column display on wider screens so it's not all squished.
• FIX: Canonical URLs for listings
  Before you could put any text in the url and it would work.
• FIX: Permanent listings with no expiration date now don't expire!
  Really not sure how that one made it through q+a

If you know of any other showstopper bugs in Classifieds let me know, I can look at fixing them in an update of this mod until @NixFifty releases his next version