[MERGE] [BUG 363837] Catch OSError to make diff log debug message instead of passing win32 specific exception to stderr

[Ian Clatworthy]

Ian Clatworthy has voted tweak.
Status is now: Conditionally approved
Comment:
director -> directory in NEWS. I'll make that tweak, add the exception 
to the mutter as Martin suggested, and merge.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3Cfuninal891aefr374gUYAxe124vaj_firegpg%40mail.gmail.com%3E
Project: Bazaar