Allow a lot of commands to be sent from the console.
Examples:
 /rg addmem <id> <player> -w <worldname>
 /rg flag <id> <flag> -w <worldname> <flagvalue>
 /rg remove <id> -w <worldname>
Command blocks are currently untested.
List of commands: flag, priority, parent, remove,
 addmember, removemember, addowner, removeowner