Add support for the NodeLabel Parameter plugin

Add support for using the NodeLabel Parameter plugin to
specify which node should run a job when triggering a
parameterized build.

Requires the Jenkins NodeLabel Parameter Plugin:
https://wiki.jenkins-ci.org/display/JENKINS/NodeLabel+Parameter+Plugin

Change-Id: Ie947a2a3069b477419db7eaa35307088712467e3
Merge "Add support for the NodeLabel Parameter plugin"