add RFC3339 / ISO timestamp?

[ssbertilson]

RFC 3339

logformat_list.append({'regexp':"(?P[0-9]{4})-(?P[0-9]{2})-(?P[0-9]{2})T(?P[0-9]{2}):(?P[0-9]{2}):(?P[0-9]{2})(?P.[0-9]+)?(?P[-+][0-9]{2}:[0-9]{2})", 'name':"RFC 3339 / ISO", 'description':"%Y-%m-%dT%H:%M:%S-%z"})

Not sure how to express SUBSEC in the description, so left it out.