add metrics for ExecutorService and ThreadFactory
'wrappee' sounds silly, renaming
add javadocs for java.util.concurrent instrumentations
implement ExecutionService instead of inheriting from AbstractExecutionService
rename underlying implementations as 'delegate'
use MetricRegistry#name instead of doing concatenation manually
use a Meter for completed tasks
make Metric members private and retrieve them from the registry for testing
format to adhere to project code convention
mark fields as final, removed a stdout statement
use meters for 'created' and 'finished'/'terminated' metrics
have both test classes terminate the generated threads cleanly
Added new constructors to HealthCheckServlet and MetricsServlet

Making it possible to assign registries via constructor rather than via
ServletConfig.
Useful for programmatic embedding and test scenarios.
Adhere to coding standard
Added some more "final"s in Test cases
Manually merge upstream into pullrequest 438
Merge pull request #438 from jhberges/master

Assign registries to HealthCheck/Metrics-Servlets via constructor
Updated relnotes and contributors.
[maven-release-plugin] prepare release v3.0.1
[maven-release-plugin] prepare for next development iteration