allow passing of js file name in bundled mode (for renaming main.js)

[Fishrock123]

This should allow a different entry other than main.js and use the parent path of that as the bundle file, in both disk and zip-bundle mode.

This used to work but some things needed changing for bundled mode to work, the relevant code is at

rustyduk/src/main.rs

Lines 153 to 170 in 3797dd1

	let entry_file: String = "main.js".to_owned();
	// TODO(Fishrock123): support renaming of main.js
	// If there are free arguments (i.e. not an option or past `--`)
	// if !matches.free.is_empty() {
	// let possible_entry = matches.free[0].clone();
	// If we we passed a .js file,
	// if Path::new(&possible_entry).ends_with(".js") {
	// entry_file = possible_entry;
	// } else {
	resource::check_set_zip(&base_path);
	// }
	// }
	duk::push_string(ctx, "nucleus.dofile('");
	duk::push_lstring(ctx, entry_file);

and entry_file is the variable that should be altered.