Expose "server" and "dedicated" to Lua scripts

This adds isserver and isdedicatedserver global variables to Lua.

Both are clientside and should not be used in anything gamelogic-related.

src/lua_script.c

@@ -326,6 +326,12 @@ int LUA_PushGlobals(lua_State *L, const char *word)
 			return 0;
 		LUA_PushUserdata(L, &players[secondarydisplayplayer], META_PLAYER);
 		return 1;
+	} else if (fastcmp(word,"isserver")) {
+		lua_pushboolean(L, server);
+		return 1;
+	} else if (fastcmp(word,"isdedicatedserver")) {
+		lua_pushboolean(L, dedicated);
+		return 1;
 	// end local player variables
 	} else if (fastcmp(word,"server")) {
 		if ((!multiplayer || !netgame) && !playeringame[serverplayer])