put changeSet behind a WeakReference
singleton NullChangeLogParser to reduce memory footprint
faster lookup by node name for NodeList
support @XstreamConverter annotation
User.getBuilds() is crazy-expensive, since it iterates over all builds. Restrict it to the most recent builds.
use LRU map for certain strings
use immutable collection for AbstractBuild.culprits

Conflicts:

	core/src/main/java/hudson/model/AbstractBuild.java
reduce footprint on TestResultAction.testData
mkdirs() is expensive on Windows, so don't do it on every getRootDir()
we shouldn't try to agressively load changesets, since they are now lazily loaded

Conflicts:

	core/src/main/java/hudson/WebAppMain.java
Jenkins.getItems() is quite expensive with a lot of items in an access controled environment. Let's try to avoid access control checks for some well known AuthorizationStrategies
LRU cache on MailMessageIdAction.messageId
Added possibility to delete matrix job with all its sub-builds (configurations)
osx: "jenkins" user created by installer should be a hidden user.
Merge pull request #348 from mc1arke/JENKINS-10432

JENKINS-10432 - Adding wiped out workspace as a reason for no workspace
Merge branch 'JENKINS-7096' of https://github.com/mc1arke/jenkins

Conflicts:
	changelog.html
[FIXED JENKINS-11353]
Now recognises test results created by the maven-soap-ui plugin
[maven-release-plugin] prepare release jenkins-1.448
[maven-release-plugin] prepare for next development iteration
updated changelog for release