General tidying up

- Remove 1.6 language features
- Whitespace consistency
- Fix typos
- Move version logic into its own class
VersionUtil updates

- added test
- added todo about moving to librato-java project
LibratoUtil updates

- added test
- removed a little bit of repetition
Merge pull request #30 from librato/cvandyck/tidy

tidy up metrics-librato