Thanks to Elric for adding dpmaster support!

Thanks to Elric for adding dpmaster support!
slist command renamed to net_slist, net_inetslist command added
"heartbeat" command notifies master server(s) of your server's presence (this is automatic, but you can force a heartbeat)
sv_master1 through sv_master4 cvars contain master server addresses, they all default to "" (none), this may change if someone hosts a darkplaces master server and wants it added to the defaults...  (note: these cvars ARE saved to config)
com_modname contains the currently running mod directory name (for example id1, darkplaces, transfusion, etc)
some Con_DPrintf's have been added to the server query code, so if you want to know if people are checking out your server, it should tell you about it now (I think?)
some Con_DPrintf's exist in the inetslist code so you can watch the packet flow

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@2432 d7cf8633-e32d-0410-b094-e92efae38249