logLevelInvalid for bad function calls and invalid data formats.

include/core.h

@@ -43,6 +43,8 @@ int lcoreTakeScreenshot( lua_State *L );
 int lcoreSetConfigFlags( lua_State *L );
 int lcoreTraceLog( lua_State *L );
 int lcoreSetTraceLogLevel( lua_State *L );
+int lcoreSetLogLevelInvalid( lua_State *L );
+int lcoreGetLogLevelInvalid( lua_State *L );
 int lcoreOpenURL( lua_State *L );
 /* Cursor. */
 int lcoreShowCursor( lua_State *L );