fix(logger): massage logspout for app name

Incoming messages from logspout take on the form of something like
this:

    2014-07-31 20:19:28  2014-07-31T20:19:28Z aa2e7309f8e4 <CONTAINER_NAME>[1]: <MESSAGE>

Application container names used to look like this:

    peachy-waxworks[web.7]:

Now it looks more like this:

    peachy-waxworks_v2.web.7[1]:

Whether we need to do some customization for backwards compatibility is
up for discussion, but optionally parsing for this string makes the
regular expression backwards-compatible as well as allowing us to
search for this specific string type.