Merge pull request #23 from JensRantil/benchmarks

Benchmark tests for `process*(...)`
Make `submit()` return its errors

* Logging of the errors is now done by the caller.
* This change makes it possible for the caller to decide how to handle
  errors. Ie. retry etc.
Add deadline to submission

This makes it possible for the caller to decide how to handle things
when deadlines are passed. See [1] for discussion about this.

[1] https://github.com/bitly/statsdaemon/pull/22#issuecomment-28012478
Merge pull request #22 from JensRantil/warn-lag

Log if we are struggling to keep up with metrics
process with gofmt
document persistCountKeys better
Merge pull request #25 from Dieterbe/cleanups

Cleanups
added receive counter and recieve-counter option
Merge pull request #26 from torkelo/master

Added receive counter and recieve-counter option
Parallelize `processTimers(...)`

If you have multiple different timers then this will speed up the
processing time.
Parallelize `processTimer(...)`
Go formatting