XF Addon [2.2.X] User Mentions Improvements 2.10.1

Improvements to XenForo's user mentions system.
This addon is does not handle super-large group membership well.

Features:

• Mentionable user groups.
  • Customizable icon per group (small + large).
  • Membership can be viewed on the front-end.
  • User group may be private, at which point only members can tag or view that group.
  • Permission to tag taggable groups.
  • Admin privilege to view all taggable groups.
• User group mentions supports the following:
  • User profile posts/comments.
  • Posts/Threads.
  • Reports
• Opt-in, send an email to the user who is mentioned/quoted:
  • global option to enable/disable.
  • permission to receive mentioned emails.
  • configurable default for users on account creation.
• Editor integration. Copying & pasting a user group tag link is transformed into @usergroup
• User mentions can be disabled per forum per user group

See the add-on Username Restrictions to prevent users signing up using a usergroup name.

New Permissions

• Enable User Mentions
• Receive Mention Alert Emails
• Receive Quoted Alert Emails
• Mention User Group
• View Private Groups

Options

• Allow mention alert emails
• Allow quoted alert emails
• Send quote emails only on unreplied threads
• Mention/Quote Snippet length
• Default usergroup avatar (small)
• Default usergroup avatar (large)
• Block mention rendering if the user has no permissions to use mentions
• Return permission denied instead of not found if lacking permissions to view a user group
• Public user group - users per page