Rename metrics-jetty9 to metrics-jetty9-legacy
Add metrics-jetty9 for Jetty 9.1 and higher
Add note regarding absolute attribute on annotation
Allow @Metric on methods and parameters
Add @Inherited and @Documented on all type annotations
Allow annotations on constructors
Merge pull request #506 from joschi/jetty-9.1

Upgrade to Jetty 9.2.0
Replaced Jetty-specific Request with Servlet API interfaces.