avoid intermediate checks of Mockito
Clarify the docs.
Clarify metrics-servlet.
Clarify metrics-servlets.
Update release notes.
Bump to 3.0.0-SNAPSHOT.
Upgrade to Servlet API 3.1.
Upgrade to Jackson 2.2.2.
Upgrade to Jetty 8.1.11.
Tiny doc fix.
Fix typo.
Added a list of third-party libraries.

Closes #417.
And link to it.
Add link to wicket-metrics project.
Merge pull request #418 from vertti/patch-1

Add link to wicket-metrics project.