Merge pull request #23 from gssiyankai/master

[FIXED JENKINS-22237] Gradle available versions should be in descending order.
[FIXED JENKINS-24329] Update Go crawler to handle download site changes.

The download page now provides direct, absolute URLs and we're now more lenient
about picking up links from the page, as the filename regex will handle things.
Allow selection of specific JDK 8, not just the latest.
Merge pull request #24 from larrys/master

Allow selection of specific JDK 8, not just the latest.
I shouldn't edit after I've tested...
Merge pull request #25 from larrys/master

I shouldn't edit after I've tested...