[FIXED JENKINS-15576] Label's Load Statistics queue length based on
label assigned to job rather than to item in build queue.
Test cases for [FIXED JENKINS-15576]
Merge branch 'master' of https://github.com/laurence-h/jenkins.git
Merge remote-tracking branch 'upstream/master'

Conflicts:
	changelog.html
	test/pom.xml
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Small comment changes in LabelLoadStatisticsQueueLengthTest
Merge with changes from https://github.com/jenkinsci/jenkins/pull/742
Merge pull request #620 from laurence-h/master

[FIXED JENKINS-15576] Label's Load Statistics queue length based on label assigned to job rather than to item in build queue.