porting test_err_redirection to osx
porting test_err_redirection to osx

rsmith31415/sh,rdhyee/sh,jakirkham/sh,amoffat/sh,twocngdagz/sh,lwgarmstrong/sh,pdelong42/sh,hacosta/python-sh,pombredanne/sh,simudream/sh,germangh/sh,achernet/sh,ppannuto/sh,z-fork/sh,hacosta/python-sh,amoffat/sh,Stupeflix/sh