Test result page keeps identifying tests as age 1

If a test has not been viewed, the age will keep being 1.
This is because getFailedSince()/failedSince is lazy loaded.
Without having viewed the CaseResult that method is never
called and the prev.failedSince returns '0' which may or may
not be accurate.
http://jenkins.361315.n4.nabble.com/Problem-with-Age-column-on-Test-Results-tab-td3172208.html
[JENKINS-20739] Filter descriptors before adding them to hetero-list.

This allows implementations of DescriptorVisibilityFilter to hide items
with descriptors from users to prevent them from being added via the UI.

This is already implemented in /lib/hudson/newFromList/form.jelly, but
nowhere else.
Added logging when filtering descriptors.
updates German translation

Since 'Job' was renamed to 'Item', this translation should be updated
Update sidepanel_de.properties
Update newJob_de.properties
Abstract username case sensitivity into an extension point
[JENKINS-22247] Provide an extension point to define user id case sensitivity contract

* Fix up bad merge
Use a dedicated descriptor
Updating the pull request in light of comments

- Removed the Legacy strategy completely
- Moved the strategy to an aspect of the security realm
- Separated the strategy for Users from Groups because... well it might be necessary for some
- Moved IdStrategy from inner class of User into top level class
Remove repo file from RPM. https://issues.jenkins-ci.org/browse/JENKINS-22690
[FIXED JENKINS-22698] Add indicator that build queue is filtered.
[FIXED JENKINS-22699] Add option to archive only if successful
Updated w.r.t. pull request review comments
Fix test
[FIXED JENKINS-22720] Only call getAllItems in recursive ListView
Fixing JENKINS-22750, regression introduced in JENKINS-21394
Fixed test and refined behaviour
Annotate hudson.Util methods.

The change adds annotations for all methods inside the class. The initial idea - enforce checks of symlink methods to prevent NPEs on Windows platforms.

Signed-off-by: Oleg Nenashev <o.v.nenashev@gmail.com>
Move entries older than last year to changelog-old

The current changelog is *more than twice as long* as the "archive".
So it could really use some trimming. I propose to always keep the
current and previous years' entries.

Second half of the change: Remove the old entries (2012 and older).