User has to choose a custom installation.
There are two choices:
- Start at boot as "daemon" (enabled by default)
- Start at boot as "jenkins" (disabled by default)

If user disables the first and enable the latter, the installer
will create a new user "jenkins" and new group "jenkins"
(if they do not exist), chown JENKINS_HOME to jenkins:jenkins
and set up launchd job to run Jenkins as "jenkins"

Also fixed some permission errors that PackageMaker complains about
when building the package.

Also PackageMaker xml file reformatted to be more readable

[JENKINS-11248] Build fails on "Deploy artifacts to Maven repository" due to trying to upload parent POM twice for release artifacts.

[JENKINS-12177] Zero executors on master is no longer valid

Fixed a bug in Winstone where a failure during request processing can
put Winstone out of sync with the next request.

Conflicts:
	changelog.html

[FIXED JENKINS-12315] Location of the temporary file 'Maven Global Settings' incompatible with release: prepare

Fixed FindBugs reported bug in initialDelay calculation - actually this would probably only go wrong once in 10000 years or so, but better be safe ;)

Follow up fix for 77a97460, also incorporating the equivalent in ac283ad7

Align animal-sniffer annotations with version of animal-sniffer-maven-plugin (1.7)
Thanks!

if the check fails miserably, report the error accordingly.

Fixed hash DoS problem.
(cherry picked from commit 5ef902bb)

Conflicts:

	changelog.html

Fixed hash DoS problem.

This prevents the load spike at midnight and other known time/date.

Tom Huybrechts reported an incompatibility problem with some plugins (batch task?), so removing the final keyword