[JENKINS-20935] - Added a monitoring page, which provides links to JavaMelody actions

This implementation reduces number of management actions on node dashboards.

Improves https://issues.jenkins-ci.org/browse/JENKINS-20935

Signed-off-by: Oleg Nenashev <o.v.nenashev@gmail.com>

![newmonitoringlayout](https://f.cloud.github.com/assets/3000480/1844768/64003a10-7551-11e3-829d-10626912b8e4.png)