Detect GOG install path

code/sys/sys_unix.c

@@ -47,6 +47,9 @@ static char homePath[ MAX_OSPATH ] = { 0 };
 // Used to store the Steam Quake 3 installation path
 static char steamPath[ MAX_OSPATH ] = { 0 };
 
+// Used to store the GOG Quake 3 installation path
+static char gogPath[ MAX_OSPATH ] = { 0 };
+
 /*
 ==================
 Sys_DefaultHomePath
@@ -106,6 +109,17 @@ char *Sys_SteamPath( void )
 	return steamPath;
 }
 
+/*
+================
+Sys_GogPath
+================
+*/
+char *Sys_GogPath( void )
+{
+	// GOG also doesn't let you install Quake 3 on Mac/Linux
+	return gogPath;
+}
+
 /*
 ================
 Sys_Milliseconds