MINOR: ring: add "-r" to "show events" to dump in raw mode (undoes "-s")

MINOR: ring: add "-r" to "show events" to dump in raw mode (undoes "-s")

In anticipation for a possible future change of the default output which
might eventually become sanitized by default, let's add "-r" which does
the opposite of "-s", and turns the output back to raw. This can be used
by tools trying to be future-proof that do not want to depend on the
default setting.