Better buttons into popups

[FIXED JENKINS-20514] Add a core extension point to allow plugins to con...

[FIXED JENKINS-20514] Add a core extension point to allow plugins to contribute to the checking of assigned labels

[FIXED JENKINS-8815] Fixed issue where CLI required giving Overall read ...

Conflicts:
	core/src/main/java/hudson/cli/CLIAction.java

* Adding a warning message when HudsonTestCase and JenkinsRule reach the configured timeout. This message will be very useful to diagnose test failures caused by timeouts.
* Adding a mechanism to allow users running tests in slow systems can change the default timeout. Now they can change this value using the environment variable "jenkins.test.timeout" expresed in seconds. Example: mvn test -Djenkins.test.timeout=300

CLI hits "/cli", so the server needs to respond to this endpoint.

Test for the existence of /var/run/jenkins before trying to chown it in
the Debian post-install script.

Added test unit.

Ensures that the directory /var/run/jenkins exists before the installer
script attempts to chmod it.

Hold on to the lease until the very end.
Previously, the lease was only held until the main build section is over, before publishers start running.

Reproduced the problem. Workspace is getting released prematurely, before publishers run. This has all sorts of serious problems.

This changes the hard-coded display name in the breadrumb bar to match
the localized message used in Configure Global Security/Access Control

[FIXED JENKINS-14380] hudson appears in a the webpage title

provide localization for HudsonHomeDiskUsageMonitor.getDisplayName()