[FIXED JENKINS-9397] Added convenience method to hudson.util.io.Archiver to get the Unix mode (if appropriate) for a file, and modified TarArchiver and ZipArchiver to utilise this to get and set the Unix mode for files whent they're being archived.

Conflicts:
	changelog.html
	pom.xml
	test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java

the UI.

Also, for the core build, require that all the dependency licenses are
available.

so don't preprend ${rootURL} .. thx alexlehm

apply to child configurations as well.

[FIXED JENKINS-7537] reports indicate that exec(2) from multi-threaded app now works on Snow Leopard. Also see JENKINS-4012

this and the previous commit constitutes the fix.
Also added a test case.

we are looking for dependencies since the last successful build
and not since the last previous not failed build

The URL is used in many more places than just E-mail Notification, but people who do not send emails from Jenkins tend to overlook it and do not think it is a setting that will affect them.

Submitted by Aurélien COUDERC

so doesn't really belong here.. will add in wiki instead.