XF Addon [2.2.X] Alert Improvements by Xon 2.12.2

A collection of improvements to the XenForo Alerts system.

This add-on requires php 5.6 or newer.
This add-on requires XF 2.0.10 or newer.

Do not use MySQL statement-based replication with this add-on

Features
For threads/conversation/profile pages, automatically marks alerts as read from content on a given page when viewed.
Mark unread link for individual alerts on the Alerts page.
Supports the following add-ons:
Content Ratings 1.3.x
Global Optional, Alert summarization by selected content type or user
User Option to prevent marking as read when accessing /accounts/alerts page.
User Option to prevent summarization when accessing /accounts/alerts page.
User Option to adjust summarization threshold
Supported content types for alert summarization
Posts, Conversation, Profile post, profile post comments Likes
Ratings (From Content Ratings)
Various conversation related alerts from Conversation Essentials for XF2
Performance impact
Adds an extra column to xf_alert.
Code:
alter table xf_user_alert summerize_id add int(10) unsigned DEFAULT NULL
1 extra SELECT query per thread page request when the user has more than zero active alerts.
If there are alerts to mark as read, then an extra UPDATE is required.
Alert Summarization Performance impact
On accessing alerts above the summarize threshold, fetches all unread alerts and attempts to group them in PHP.
On successfully generating summary alerts, 2 queries are done. 1 insert to add the summary alert, 1 updating summarized alerts