Add-ons Alert Improvements by Xon 2.10.13

• Fix unsetting "Pop-up auto-read" for some XF stock alerts would fail to be respected when those alerts are generated

• Fix "getSvAlertPref(): Return value must be of type array, null returned" when adding a user via the admincp
• Force a consistent mysql locking ordering of affected user records when a user receives a reaction

• Fix alerts grouped by user could occur event if the alerts by a user was less than the configured threshold
• Fix new installs did not migrate alert preferences
• Fix migrating alert preferences would block the installer
• Fix alert preferences where not respected during alert migration from stock to add-on configuration
• Adjust text around the alert pop-up marking alerts as read behavior
• Use a separate css class for the recent alert marker
• Convert confusing named "Alerts pop-up does not mark alerts as read" checkbox to "Alert pop-up read behavior" with the options: "Always mark alerts as read"/"Never mark alerts as read"/"Use per-alert configuration"
• Add style properties "Show recent/unread alert icon on alert" and "Unread/Recent alert icon", disabled by default (previously was enabled)