Reliably hides the invite popup by waiting for PARTY_MEMBERS_CHANGED (older method broke in 3.1). Reliably sets loot type to FFA by waiting until the group is formed. Avoid sending duplicate invitations from duplicated API events. Avoid cross-invitations and the related errors (to the largest extent possible). Partial work-around for issue where friend names are nil just after login -- records invitation and attempts to process it when the friend list is really available. There's a potential...
