Little fixes

- typo in README
- Use static methods in LibratoUtil
- Ignore warnings about unused builder methods
- Avoid double shutdowns on the executor
- Dry up static logic in MetricsLibratoBatch, close the InputStream
- Remove @Override for interface methods since we are using Java 1.5.
Oops make sure to read the next line :)
Merge pull request #28 from collinvandyck/little-fixes

Little fixes