- Change runtime standalone detection:

* com_standalone now read-only
  * add new cvars com_basegame, com_homepath
  * standalone now automatically detected when com_basegame is set to something different than baseq3 and no id pak pk3s are found
  * This fixes https://bugzilla.icculus.org/show_bug.cgi?id=4699
- Replace a few hardcoded string literals with macros
- Add checks for Team Arena PK3s to FS_CheckPak0()

code/ui/ui_main.c

@@ -65,7 +65,7 @@ static const int numNetSources = sizeof(netSources) / sizeof(const char*);
 static const serverFilter_t serverFilters[] = {
 	{"All", "" },
 	{"Quake 3 Arena", "" },
-	{"Team Arena", "missionpack" },
+	{"Team Arena", BASETA },
 	{"Rocket Arena", "arena" },
 	{"Alliance", "alliance20" },
 	{"Weapons Factory Arena", "wfa" },