Thanks Matias Bordese. (a few modifications of my own)

  in a `with` statement.  Contributed by Giampaolo Rodola.

in the _posixsubprocess C extension module it would unintentionally close the fds and raise
an error.

in the _posixsubprocess C extension module it would unintentionally close the fds and raise
an error.

The fix is to charset.py, which was not doing the encoding to the
correct output character set when doing a body_encode for either
the shift-jis or euc-jp charsets.  There's also a fix for handling
a bytes input in encoders.py.

Patch by Michael Henry, comment changes by me.

Patch by Denver Coneybeare at the PyCon 2011 Sprints.

when test_subprocess was run.