Fix unicode handling in Python 3 and Python 2. There are currently two
failure modes. In python 2, swiftclient fails to log in debug mode if
the account name has a non-ASCII character. This is because the account
name will appear in the storage URL, which we attempt to pass to the
logger as a byte string (whereas it should be a unicode string). This
patch changes the behavior to convert the path strings into unicode by
calling the parse_header_string() function.
The second failure mode is with Python 3, where http_lib returns headers
that are latin-1 encoded, but swiftclient expects UTF-8. The patch
automatically converts headers from latin-1 (iso-8859-1) to UTF-8, so
that we can properly handle non-ASCII headers in responses.
Change-Id: Ifa7f3d5af71bde8127129f1f8603772d80d063c1