Support for native in leg, and start moving native tests to a specific test suite.

frog/tests/native/test_config.dart

Index: frog/tests/native/test_config.dart
===================================================================
--- frog/tests/native/test_config.dart	(revision 0)
+++ frog/tests/native/test_config.dart	(working copy)
@@ -6,10 +6,10 @@
 
 #import("../../../tools/testing/dart/test_suite.dart");
 
-class FrogTestSuite extends StandardTestSuite {
-  FrogTestSuite(Map configuration)
+class FrogNativeTestSuite extends StandardTestSuite {
+  FrogNativeTestSuite(Map configuration)
       : super(configuration,
-              "frog",
-              "frog/tests/frog/src",
-              ["frog/tests/frog/frog.status"]);
+              "frog_native",
+              "frog/tests/native/src",
+              ["frog/tests/native/native.status"]);
 }