changed VData system again, renamed src/script to src/lang and added src/c.mers, which is an example something that currently does not work properly due to the VData implementation (and serves as a reminder to fix the issue)

mers/tests/test_in_mers.rs

@@ -15,7 +15,7 @@ fn run_all() {
                 let mut file = File::new(fs::read_to_string(file.path()).unwrap(), file.path());
                 // has to return true, otherwise the test will fail
                 assert!(matches!(
-                    parse::parse(&mut file).unwrap().run(vec![]).data().0,
+                    parse::parse(&mut file).unwrap().run(vec![]).inner_cloned(),
                     VDataEnum::Bool(true)
                 ));
             }