XF2 Add-on User Promotion on Profile Update 2.4.2

[virgilio183]

Allows an Custom Fields to match an empty rule if selected.

Preforms a user promotion when:

• A user updates their own profile (Routes under /account).
• When admin's edit a user's profile.
• When a user upgrade is being applied/removed

Modifies notification/user promotion criteria with:

• Allows a Custom Field to match an empty rule

Performance impact

• User promotion is rebuild when they update their profile.

Contributing features or bug fixes
Please create a Github Pull request via the "More information" link.