Add standard file headers

The author was specified as required by cpplint, but otherwise the header did
not look like the one we usually use.

Author: tautschnig

unit/util/expr_cast/expr_cast.cpp

@@ -1,6 +1,10 @@
-/*
-  Author: Nathan Phillips <[email protected]>
-*/
+/*******************************************************************\
+
+Module: Unit tests of expr_dynamic_cast
+
+Author: Nathan Phillips <[email protected]>
+
+\*******************************************************************/
 
 /// \file
 /// expr_dynamic_cast Unit Tests

unit/util/expr_cast/expr_undefined_casts.cpp

@@ -1,6 +1,10 @@
-/*
-  Author: Nathan Phillips <[email protected]>
-*/
+/*******************************************************************\
+
+Module: Unit tests of expr_dynamic_cast
+
+Author: Nathan Phillips <[email protected]>
+
+\*******************************************************************/
 
 /// \file
 /// expr_dynamic_cast for types that don't have a cast

unit/util/string_utils/split_string.cpp

@@ -1,6 +1,10 @@
-/*
-  Author: Diffblue Ltd.
-*/
+/*******************************************************************\
+
+Module: Unit tests of split_string
+
+Author: Diffblue Ltd.
+
+\*******************************************************************/
 
 /// \file
 /// split_string Unit Tests

unit/util/string_utils/strip_string.cpp

@@ -1,6 +1,10 @@
-/*
-  Author: Diffblue Ltd.
-*/
+/*******************************************************************\
+
+Module: Unit tests of strip_string
+
+Author: Diffblue Ltd.
+
+\*******************************************************************/
 
 /// \file
 /// strip_string Unit Tests

unit/util/symbol.cpp

@@ -1,4 +1,10 @@
-/// Author: Diffblue Ltd.
+/*******************************************************************\
+
+Module: Unit tests of symbol_tablet
+
+Author: Diffblue Ltd.
+
+\*******************************************************************/
 
 /// \file Tests for symbol_tablet