[FF] AMS Enhancements - Xenforo 2 1.2.6

Features:

• Show the article content above in the thread header (with page buttons if multipage article)
• Hide first post of the discussion (which is just a link to the article).
• Optionally show the article cover image (either as thumbnail or full image)
• Add a "Create Article" button to selected forums
• Link AMS and XF prefixes, so when discussion thread is created it can be set by prefix rather than just category.
• Update discussion thread prefix if article is moved to a new category or has its prefix changed.
• Move reactions from original thread when using "Convert thread to article" function.
• Copy newly posted comments to the article discussion thread.
• [NEW] Correctly prefix all table fields, template names and option variables to bring it in line with XF addon coding standards - thanks @Bob
• [NEW] Integrate prefix filter into main navigation block