support Q3A's gametype filtering (notteam, notq3a, notsingle, gametype) as in ioq3...

support Q3A's gametype filtering (notteam, notq3a, notsingle, gametype) as in ioq3 source. Has a known bug it shares with ioq3 (namely, that "gametype" "teamtournament" also matches "tournament" (in Xonotic: arena) and "team" because of retarded substring matching). ONLY the game type names ffa (anything non-teamplay not having a more special name), tournament (Arena), single (maxplayers == 1), team (anything teamplay not having a more special name), ctf (ctf, duh) are supported, as we currently have nothing matching Q3A's oneflag, obelisk, harvester and teamtournament modes!