[AndyB] User upgrade expired reminder 1.3

Creates a conversation when a members account upgrade has expired.
This add-on runs on the first of the month to remind the member their account upgrade has expired. It can be set to run for 1 month (default) or more months if desired.

Features:

• Conversations are created automatically via Cron entry.
• All phrases start with userupgradeexpiredreminder_ for your convenience.

Setup:
Update the options page with your Account upgrades link, Starter username and be sure to Exclude user groups.