to be used by other ComputerLaunchers to check installed java version

[JENKINS-14814] "Ping-pong" builds store excessively large CauseAction

[FIXED JENKINS-7162] Add missing parameters as defaults when called from...

Add all the job defined Parameters to the ParameterAction using Defaults
if not passed via the command line.

Reduce duplicate entries for the same plugin and version when multiple update centers are publishing similar data

* The whole point of the rule is to allow access to the helper methods, so they need to be public

* also synced up with HudsonTestCase

For instance, use PegDown Formatter and enable SUPPRESS_ALL_HTML.