debian: Fill in gecos field for jenkins user

Otherwise when Jenkins runs git, git will complain that the identity is
not set up correctly and will fail.
JENKINS-15380. Add some length checking before trying to substring.
Compare string length directly in if to get a shorter method.
German translation for permission descriptions
updated comment
Keep consistence in pendings when exception is thrown during method pop()
As this is my first look inside Jenkins codebase I not sure it's correct
but perhaps artifacts for modulebuilds should be deleted just as logs
are deleted. see https://issues.jenkins-ci.org/browse/JENKINS-17508
I did not fully test it yet, all unit tests ran fine, but didn't succeed
to run jobs inside Jenkins, due to classloader issues while running
Jenkins in Jetty, to verify deletion
adds test that looks in jobs archive with 2 builds when LogRotator set as build discarder with settings to keep only 1 build with artifacts, test searches for jars in archive for build one and build two expecting no jars in build 1 and expecting jars in build 2
add documentation to testcase.
also testing the removal of build if LogRotator is configured to discard
old builds and not only artifacts (Not needed for the issue, but an
extra test is not a luxury )
JENKINS-17508 updated the test to use @Rule and no longer extend from the old HudsonTestCase (shouldn't that one be marked deprecated?), add @ Bug and @ For as jesse suggested
JENKINS-17508 removed usage of deprecated elements in test
Prevent ClassCastException when encountering ItemGroup of
non-TopLevelItem.

This is the case for instance when encountering a MavenModuleSet which
is ItemGroup<MavenModule>
add global maven config to define default settings providers
changed the filepath#toUri call to #getRemote as per comment of @jglick
[FIXED JENKINS-17030] Enable word breaking for job names
Hopefully this helps us reduce the screen glitch
[FIXED SECURITY-67] Forbid CSS links in markup to be on the safe side.(cherry picked from commit 1e19eb3ecece1931b5363a797fd2b30f8edc6180)
[SECURITY-63] Require POST for running Groovy scripts.(cherry picked from commit 3bbb65df3a5cb2cedb1d8080d6b70697c826a4a9)
[SECURITY-63] Check RUN_SCRIPTS for /eval.(cherry picked from commit 3d03990abc68f39e7a92ed9594abb658879a6d7b)