RLVEX updates to make it more "Joe Average" friendly

Mega changes. Added N2K variant Name2Key, ability to add to "Others" list via chat command & issue other chat commands with user name OR uuid. Reformatted UserCommand structure, incorporating "ex " mandatory start-param to facilitate early "not meant for me" drop-out & prevent commands not meant for this script. Changed format to "Name:Item=Exempt," (comma for striding) - Name (or key) only needs entered once, strided list of commands can follow. EX: "jrex John Doe:rcvim=enforce,sendchat=exempt:Jane Doe:rcvim=enforce" etc. Added "add" chat command, to add a user to the "Others" list without setting any restrictions. EX: "jrex add John Resident"
Removed the trailing "s" from "secowners" buttons & commands (not list names), for uniformity with "owner" buttons & commands