ENH: Teach Update* tests to report local mod step

The CTest.UpdateCVS/SVN tests report every step with a message.  This
adds a message for the local modification step.

Tests/CTestUpdateCVS.cmake.in

@@ -110,6 +110,7 @@ if(SLEEP)
 endif()
 
 # Create a modified file.
+message("Modifying locally...")
 modify_content(user-source)
 
 #-----------------------------------------------------------------------------

Tests/CTestUpdateSVN.cmake.in

@@ -104,6 +104,7 @@ run_child(
   )
 
 # Create a modified file.
+message("Modifying locally...")
 modify_content(user-source)
 
 #-----------------------------------------------------------------------------