contrib: byteify perf.py file
This is done using contrib/byteify-strings.py. There is just one extra change
done to make sure lines don't get longer than 80 chars.
# skip-blame because just b'' prefixes.
Differential Revision: https://phab.mercurial-scm.org/D4422
#if no-windows no-osx
$ mkdir -p xdgconf/hg
$ echo '[ui]' > xdgconf/hg/hgrc
$ echo 'username = foobar' >> xdgconf/hg/hgrc
$ XDG_CONFIG_HOME="`pwd`/xdgconf" ; export XDG_CONFIG_HOME
$ unset HGRCPATH
$ hg config ui.username 2>/dev/null
foobar
#endif