JmxReporter: When Registering a Bean we check if its ObjectName is already Registered and if it is we unregister before registering the ObjectName again
add ability for subclasses to spoof host names per ganglia spec
add ability for subclasses to spoof host names per ganglia spec
update test class to use new host name method
fix comment
add spoof bit on second packet (missed in previous commit)
add more helpful method docs
Update master
Update master
Add support for formatted messages to HealthChecks

This adds convencience methods to automatically format `HealthCheck`
messages using `String.format(format, args)`:

For healthy `HeathChecks`:
```java
Result.healthy("latency: %d", latency);
```

For unhealthy `HealthCheck`s:
```java
Result.unhealthy("timed out after %dms, connecting to %s:%d",
    timeout, host, port);
```
Upgrade to HttpClient 4.2.1.
Change metrics-httpclient to be in line with 4.2.
Update release notes.
Handle long periods of inactivity without messing up forward decay priority sampling.
Clean up ExponentiallyDecayingSample and its tests.
Merge pull request #235 from berngp/master

JMX Reporter: Avoid javax.management.InstanceAlreadyExistsException when registering.
Update release notes.
Merge pull request #235 from berngp/master

JMX Reporter: Avoid javax.management.InstanceAlreadyExistsException when registering.
Update release notes.
Stop caching a histogram's arrays.
Upgrade simplespec.