Refactor

This renames the "mock" code to "reference" because that's really what
it is.  Also, some code has been moved from the CDM repo to a common
utility directory so that it can be included here, and the oemcrypto
unit tests can now be built without having access to a current CDM
repo.

There are no functionality changes in this CL.

util/include/disallow_copy_and_assign.h

@@ -0,0 +1,15 @@
+// Copyright 2018 Google Inc. All Rights Reserved.
+
+#ifndef WVCDM_UTIL_DISALLOW_COPY_AND_ASSIGN_H_
+#define WVCDM_UTIL_DISALLOW_COPY_AND_ASSIGN_H_
+
+namespace wvcdm {
+
+#define CORE_DISALLOW_COPY_AND_ASSIGN(TypeName) \
+  TypeName(const TypeName&);                    \
+  void operator=(const TypeName&)
+
+
+}  // namespace wvcdm
+
+#endif  //  WVCDM_UTIL_DISALLOW_COPY_AND_ASSIGN_H_