D3BFG gets the username from Steam, in the GPL release it just
uses the hostname.
Now it's possible to set a custom name with the ui_name CVAR
(like in classic doom3). If ui_name is empty ("") the hostname
is used.
The window losing focus in MP resulted in the console being spammed
with "changing com_pause not allowed in Multi Player" (or similar)
messages. Added CVAR_NOCHEAT flag to com_pause to get rid of that.