JENKINS-7280 - Allow filtering of the Run Paramters List

Hi,

This is a change to try and address the following issues:
https://issues.jenkins-ci.org/browse/JENKINS-7280 - run parameters show builds that have not completed or have failed / unstable
https://issues.jenkins-ci.org/browse/JENKINS-6744 - Need "Good Run" parameter

It adds a new 'Threshold' dropdown to allow you to select the minimum result which a build must satisfy to be included in the dropdown for selection.
It also includes an 'ALL' option to retain existing behaviour.

Please review and provide feedback.
I am new at this so all feedback welcome :)

Messed up my previous pull request so trying again: https://github.com/jenkinsci/jenkins/pull/728

thanks
Geoff