Alert Improvements by Xon 2.12.2

• Fix access check when unsummarizing alerts. This could allow deleting arbitrary alerts for other users, but did not leak contents of that alert.

• Package correct version of add-on's javascript files, fixes mark read/unread links.

• Fix an alert count query being deadlock prone.
• Rip out XF2.0 support & Content Ratings for XF2.0 support
• Update various reaction summary phrases to be more consistent with singular reaction alerts
• Update alert mark-as-read option hint phrases to be hopefully less confusing
• Add per-alert "mark read" link (like "mark unread", it uses ajax to reload the alert)
• In Alerts pop-up page
  • Fix that just read alerts where being pushed under unread alerts when splitting grouping unread/read alerts
  • Move recent new alert marker to be under the user avatar

• Fix "Call to a member function updateUnreadCountForUser() on null" during hourly cleanup
• Remove overlay flag on alert preferences link on alert page

• Fix mark-as-read sets the wrong alert total on returning json
• Make "show all" alerts link select the "all" filter
• Rebuild user alert totals as as versions 2.8.0 to 2.8.3 had bugs where these where not updated as expected
• Update alert pruning patch for large forums to work with XF2.2 pruning, and to update alert totals for users who have expired alerts

• Tweak read/unread/recently-read row styling, move read/unread separator as css class rather than inline styling
• Restore per-alert 'mark read' link

• Fix XF2.2 error; "method isRecentlyViewed is not callable on the given object"

• Requires XenForo 2.1+
• Requires php 7.0+
• Recommend Warning Improvements 2.5.4 to support "Anonymize warning issuer" feature & Alert Improvements
• Recommend Thread Starter Alerts 2.2.0 to support "auto read" feature
• Now depends on Standard Library by Xon
• Supports XF2.2+
• On browser prefetching, do not automatically mark alerts as read.
• Add "Alert summarize limit" option to prevent unexpectedly large number of alerts being checked for summarization
• Add alert summarize flood-checking to determine if alerts page or alerts pop-up triggers alert summarize
• Remove per-alert 'mark read' link, replace with a bulk mark read/unread system supporting selecting by day
• Rework alert mark-as-read logic;
  • On Alerts page and alerts pop-up, only marks viewed alerts as viewed/read rather than all.
  • Support XF2.2 "auto read" alerts feature (and marks thread starter alerts as auto_read=0), back-ported to XF2.1
  • Ensure consistent behaviour between XF2.1 & XF2.2
• Tweak alert pop-up footer to be consistent between XF2.1 & XF2.2

• When pruning alerts; Reduce maximum batch size, and back-off by 1 second between prune attempts

• Fix unexpected extra queries when a user doesn't have unread alerts