Add getReferenceInfo to IBase.

Also added a IMPL_STUB_IMPL for HIDL reserved methods that:
* add a method with the same name and signature
  to BnHwFoo
* BnHwFoo::onTransact will call BnHwFoo::method instead of
  _hidl_mImpl->method
* Content of IMPL_STUB_IMPL will go to BnHwFoo::method.

Test: make and tested NFC / light / audio
Test: hidl_test

Change-Id: I85f6314450178c02c7bcba91c8a9fffbce822c76
diff --git a/Method.h b/Method.h
index 5a2ad8a..f9d7b8b 100644
--- a/Method.h
+++ b/Method.h
@@ -38,7 +38,8 @@
 enum MethodImplType {
     IMPL_HEADER,
     IMPL_PROXY,
-    IMPL_STUB,
+    IMPL_STUB, // overrides the code in onTransact; IMPL_STUB_IMPL will be ignored
+    IMPL_STUB_IMPL, // use this->method() instead of mImpl->method()
     IMPL_PASSTHROUGH,
 };