ceph: Make stdout/stderr always output Unicode (UTF-8)

ceph: Make stdout/stderr always output Unicode (UTF-8)

If a stream is not interactive, then under Python 2, then the encoding for
stdout/stderr may be None. This means that it's not possible to print Unicode
characters since the encoding will fall back to ASCII.

This explicitly makes sys.stdout/sys.stderr always use UTF-8 encoding for
strings, regardless of the system's local or if the console is interactive or
not.
This matches the existing tests that assume that output of non-ASCII pool names
will be UTF-8 encoded.

When outputting raw binary data (such as the CRUSH-map), we must bypass the
codec and write directly to raw streams (since the new stream will only accept
ASCII byte-strings or Unicode strings).

Signed-off-by: David Coles <dcoles@gaikai.com>