add single files, secure server, hello world

single_file_tests/term.dart

@@ -0,0 +1,11 @@
+#!/usr/bin/env dart
+
+import 'dart:io';
+
+main() {
+  if (stdioType(stdout) == StdioType.terminal) {
+    print("Is term.");
+  } else {
+    print("Not term.");
+  }
+}