Embed the log line reader in Shuttle

And rename it as it shared a name with a basic go interface, which is
bad.
UseStdIn doesn't belong in config anymore

Also update pebbe/util package
Bunch of cleanups

Inject the loggers so the user/caller has control of how messages and
errors get logged.

The metrics emitter is really part of the command line tool, not the
library AFAICT.

Simplify internal constructors by just passing a shuttle instead of
picking out pieces.
Make golint happy
Merge pull request #38 from heroku/additional_cleanup

Additional cleanup