Working towards initial.
Injection.
Documentation and license.
Travis fix.
README update.
Increasing the usage of metrics and integrating them more readily.

* Extracted CallUtils behind a factory and integrated the metrics library.
* Added various metrics, some which are called through the builder and some of which are there automatically.
Documentation update and minor build changes.
Upgrading to com.codahale.metrics 3.0.0-BETA3.
Adding basic metrics to FutureUtils.

- Pulled FutureUtils behind a factory.
- Added a small number of metrics to it.
Adding basic convenience features.

 * Using a String name instead of a Callable for metrics.
 * Adding a set of default retry and backoff strategies.
 * Renamed pushback->backoff by convention.
 * Other consistency improvements in naming.
Merge pull request #1 from dclements/initial

Initial work.