fixing a test failure
Fix ListJobsCommandTest failed on Windows by replace line ending
Merge pull request #826 from lmwang/windows_test

Fix ListJobsCommandTest failed on Windows by replace line ending
[FIXED JENKINS-18425]

"201 Created" response doesn't work well with a browser as the user agent.
Fixed Wiki URL
Converted to Groovy for simplification
[FIXED JENKINS-18407]

Added Queue.schedule2 to allow the caller to retrieve the existing item in the queue. AbstractProject.doBuild() changed the behavior a bit to reply 201 if the item was already found in the queue (instead of a new one created.)
Minimal refactoring for a8c3a031c068d3a356c105af42c2819dc3962124

IMO this needs further refactoring - respect separation of concerns:
it's not AbstractProject's call to trigger a node offline
removing what appears to be a left-over from the previous experiment.
Based on further conversation with the Artifactory plugin developers, revisiting this extension point.

This is a breaking change, but this extension point was added very recently, and it's based on the input from Artifactory plugin, so there's not much point in keeping one that doesn't serve the intended use case.
not sure why this works locally, but when run on Jenkins it complains

... probably because it's split in two lines
fixed test regressions
Use PNG for better transparency handling
[FIXED JENKINS-18349 JENKINS-18405]

Integrated the fix toward 1.521.
for improving the test performance, running this with the default local repository
[maven-release-plugin] prepare release jenkins-1.520
[maven-release-plugin] prepare for next development iteration
updated changelog for release
updated changelog as a part of the release
merged back the RC branch

Conflicts:
	test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java