Bunyan

- Export `bunyan.resolveLevel(NAME-OR-NUM)` to resolve a level name or number
to its log level number value:

> bunyan.resolveLevel('INFO')
30
> bunyan.resolveLevel('debug')
20

A side-effect of this change is that the uppercase level name is now allowed
in the logger constructor.

- [issue 35] Ensure that an accidental `log.info(BUFFER)`, where BUFFER is
a node.js Buffer object, doesn't blow up.

- [issue 34] Ensure `req.body`, `res.body` and other request/response fields
are emitted by the `bunyan` CLI (mostly by Rob Gulewich).

- [issue 31] Re-instate defines for the (uppercase) log level names (TRACE,
DEBUG, etc.) in `bunyan -c "..."` filtering condition code. E.g.:

$ ... | bunyan -c 'level >= ERROR'

- [pull 32] `bunyan -o short` for more concise output (by Dave Pacheco). E.g.:

22:56:52.856Z INFO myservice: My message

instead of:

[2012-02-08T22:56:52.856Z] INFO: myservice/123 on example.com: My message

- Add '--strict' option to `bunyan` CLI to suppress all but legal Bunyan JSON
log lines. By default non-JSON, and non-Bunyan lines are passed through.