Add job group description field for documentation purposes
Merge pull request #20 from olivergondza/group_description

Add job group description field for documentation purposes
Fixed NPE when onEnterBlocked() is called during startup.
Merge pull request #21 from christ66/ZD-21057

Fixed NPE when onEnterBlocked() is called during startup.

A NPE can happen if the throttle concurrent plugin is enabled and the queue is blocked.

Relates to [JENKINS-24911]
Updated type and position of the description field.
[maven-release-plugin] prepare release PrioritySorter-2.9
[maven-release-plugin] prepare for next development iteration
Merge remote-tracking branch 'jenkinsci/master'

Conflicts:
	src/main/java/jenkins/advancedqueue/JobGroup.java
	src/main/resources/jenkins/advancedqueue/PriorityConfiguration/index.jelly

Also fixed naming issue with Cloudbees Folder strategy classes