Fix defect with clothes shop checking for empty string license
Add two extra options to admin menu

Add option in admin menu for setting an extra custom line in the
server's motd message.
Add option in the admin menu for deleting Man objects. This is useful
for when the clothes switching bugs out, and the old AI player stays.
Also reformatted the code in the admin menu to align the otions with
single tab.
Fix problem with gang leader not being assigned correctly

Refactored the code that assigns the gang leader so that leader is
reassigned whenever anyone enters or leaves the gang