Add-ons Referral Contests 2 by Siropu 2.3.1

Added spam cleaner options to remove referrer and referrals. Requires the new user group permission "Use the spam cleaner to remove referrer/referrals".
Added admin option to select user groups when creating invitations from ACP. The registered user will be added to those groups upon registration.

Bugs Fixed
Issue with invitation code autocomplete on registration page where the field gets cleared up when you try to manually paste the invitation code.

• Fixed an issue with unconfirmed user table primary key index.

Added option to display top referrers widget (all time or monthly via widget settings).
Added option to enable guest message for guests that have been referred/invited by a member.
Added option to enable referrer field on registration page.
Added option to set an expiration date for invitations.
Added admin option to set custom expiration date for manually generated invitations.
Added admin option to generate invitations for a different user.
Users can now send email invitations without option "Make board invitation only" enabled.
Added user criteria option for referral count.
Widgets can now be enabled/disabled from admin options.

Bugs Fixed
Pagination limit was set to 2 on the referral list.
Other code issues.