[GROOVY-4292] Update Groovy to 1.8.9 to avoid random livelock during startup when init.groovy specified.
"GroovyInitScript.init" daemon prio=10 tid=0x00007f28d0001800 nid=0x48 runnable [0x00007f28cb79e000]
   java.lang.Thread.State: RUNNABLE
	at java.util.WeakHashMap.get(Unknown Source)
	at org.codehaus.groovy.ast.ClassHelper.makeCached(ClassHelper.java:121)
	at org.codehaus.groovy.ast.ClassHelper.makeWithoutCaching(ClassHelper.java:183)
	at org.codehaus.groovy.ast.ClassHelper.make(ClassHelper.java:170)
	at org.codehaus.groovy.ast.ClassHelper.make(ClassHelper.java:159)
	at org.codehaus.groovy.vmplugin.v5.Java5.makeClassNode(Java5.java:382)
	at org.codehaus.groovy.vmplugin.v5.Java5.makeParameter(Java5.java:403)
	at org.codehaus.groovy.vmplugin.v5.Java5.makeParameters(Java5.java:396)
	at org.codehaus.groovy.vmplugin.v5.Java5.configureClassNode(Java5.java:331)
	at org.codehaus.groovy.ast.ClassNode.lazyClassInit(ClassNode.java:262)
	- locked <0x00000000f4bfe2b0> (a java.lang.Object)
	at org.codehaus.groovy.ast...

Root cause of class loading error (on jnr.ffi.util.ref.internal.Finalizer$ShutDown) still unclear,
but easy fix is to simplify ClientAuthenticationCache.save to use FilePath.chmod,
which at least for now relies on hudson.util.jna.GNUCLibrary rather than JNR.

[FIXED JENKINS-19135] Permit a user to configure an axis with no values without throwing exceptions.
The project cannot be usefully built in this case but at least they can go back and reconfigure it.
Also fixing Layouter.Column to not throw NoSuchElementException (in violation of Iterator contract)
and thus break project overview when there is an empty Axis in the trivial list (due to an unintentional IndexOutOfBoundsException).

Added another attribute 'checkDependsOn' on <input> elements (akin to
'fillDependsOn', etc) to list up the other dependency controls, and
insert appropriate onchange events.

'checkUrl' is now just the stem portion of the URL to invoke, and
the client script builds up the query parameters.

Also [JENKINS-19042] does not seem to have made it into 1.526; seems to have been towards 1.527.

Integrated bytecode-compatibility-transformer that allows core to
do signature changes on properties that plugins might depend on.

The library performs necessary bytecode transformation to achieve this.

The first use of this is to fix plugins that looks for List
AbstractProject.triggers, thereby resolving JENKINS-18677.

For the time being, I'm not loading such compatibility annotations from
plugins, but I did code that in PluginManager. Let's see how this
feature work out for a while in the core, and if it looks stable and
solid, we'll open it up to plugins at that point.

Added a new overloaded version that works on a project.

Updated CoreEnvironmentContributor accordingly.

The code is smart enough to compute a minimum set of builds to remove to
restore order consistency.

Also cleaning up variable names to be less misleading.

Note that new File("target") is really a bad idea since we cannot predict the CWD in effect when Maven is run.
(From the standard bin/mvn launcher, it seems that it will always be *some* Maven project at least.
This may not be true for Maven run embedded from various tools.)
But leaving that as is for now, since it is not clear how else we would find the project location.
(new File(env.description().getTestClass().getProtectionDomain().getCodeSource().getLocation().toURI()).getParentFile() might work but it is pretty hacky.)

[FIXED JENKINS-18178] Reverting an inessential part of the fix of JENKINS-16301 since it broke some Maven builds.
Apparently the Maven 2 process factory fails to adequately insulate the Maven process from Jenkins library dependencies;
if you specify a build extension that can override dependencies used by Jenkins core classes!
A real fix would involve changing class loader delegation, since presumably similar bugs could still occur.

[FIXED JENKINS-18898] ToolInstallation.getHome may be null, and buildEnvVars must take that into account.

Clearer display of log messages: chronological order, and coloration of repeated vs. fresh metadata.

Also ensuring that Jenkins configuration is saved after new XML is POSTed.