copy2 vs copy in copy_selected

[Eric Firing <efiring hawaii edu>]

Hello--

While investigating merge (a beautiful piece of work, incidentally), I 
came across an aspect of its behavior that surprised me:

When merging directories, it would seem natural to me that copying a 
file from one directory to the other should preserve the modification 
time on the copy.  This would mean using shutil.copy2 instead of 
shutil.copy in the copy_selected method--correct? Is there a reason why 
this is not being done?  The copytree method does use shutil.copy2.

Thanks.

Eric