Name control

[moonpolysoft]

Allows users to control the naming of the domain and type when using jmx metrics. Values can be overridden like so:

class Blah extends Instrumented {
  override protected lazy val metricsGroup = 
    new MetricsGroup(NameBuilder("custom.domain", "CustomType"))
}

[moonpolysoft]

Put back the original method signatures on Metrics.java to avoid breakage of deployed code.

[codahale]

Got this covered in 2.0.0-BETA11-SNAPSHOT after the feature/scoped-names merge.