Allow entire membership to be selected when registering a guest for an event so the guest owner doesn't have to register for an event they don't want to do.

Allow the member (grandpa) to register his non member grandchildren for a child's event without grandpa being listed as a participant.  A simple change to the drop down list could fix this (allow the drop down to include all members not just those that have registered for the event to be selectable) so members can easily sign up/pay for others be it another member or a non member.  This would also keep the event list to only the participants as well as make the reports more accurate.