Adds the ReturnArg<k>() action (by Tim Hockin); refactors gmock-matchers.h (by Zhanyong Wan).

include/gmock/gmock-generated-actions.h.pump

@@ -1,6 +1,6 @@
 $$ -*- mode: c++; -*-
 $$ This is a Pump source file.  Please use Pump to convert it to
-$$ gmock-generated-variadic-actions.h.
+$$ gmock-generated-actions.h.
 $$
 $var n = 10  $$ The maximum arity we support.
 $$}} This meta comment fixes auto-indentation in editors.
@@ -940,6 +940,13 @@ ACTION_TEMPLATE(InvokeArgument,
 
 ]]
 
+// Action ReturnArg<k>() returns the k-th argument of the mock function.
+ACTION_TEMPLATE(ReturnArg,
+                HAS_1_TEMPLATE_PARAMS(int, k),
+                AND_0_VALUE_PARAMS()) {
+  return std::tr1::get<k>(args);
+}
+
 // Action SaveArg<k>(pointer) saves the k-th (0-based) argument of the
 // mock function to *pointer.
 ACTION_TEMPLATE(SaveArg,