Converted over to using dropwizard-protobuf

* Removed internal code for supporting protocol buffers
* Removed dropwizard-asset bundle and attempt at creating API documentation (never really worked)
* Upgraded the newrelic-api from 3.7.2 to 3.9.0
* Don't hardcode "User-Agent" everywhere, use a constant
Use more efficient packed encoding for repeated numeric fields

See https://developers.google.com/protocol-buffers/docs/proto#simple under "Specifying Field Rules"

```
For historical reasons, repeated fields of basic numeric types aren't encoded as efficiently as they could be. New code should use the special option [packed=true] to get a more efficient encoding.
```
Merge pull request #12 from jplock/jp-protobuf

Converted over to using dropwizard-protobuf
Merge pull request #13 from jplock/jp-packed-encoding

Use more efficient packed encoding for repeated numeric fields