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).
[FIXED JENKINS-23361] Add CLI commands to add jobs to and remove jobs from views.
[JENKINS-23365] Noting some nullness conditions; calcRevisionsFromBuild in particular is tricky.
Automatically disable test timeout when running in a debugger.
[JENKINS-23365] Follow-up API fixes: introduce SCM.getKey(), and add an SCMRevisionState baseline argument to checkout.
Necessary in order to produce correct changelogs by SCM plugins which actually use SCMRevisionState correctly (unlike git-plugin!).
Improved robustness of RunParameterValue so it does not break the REST API when there is invalid data.
Observed in 1.554.1:
java.lang.ArrayIndexOutOfBoundsException: 1
        at hudson.model.RunParameterValue.getNumber(RunParameterValue.java:63)
Established test baseline for Items.getAllItems with sorting.
What I hope is a more efficient Items.getAllItems, using a simpler sorting method.
Cf.: https://github.com/jenkinsci/metrics-plugin/commit/b7a2f58c977c8d1053d702e36dcc36bb1348e1aa
Merge pull request #1224 from daniel-beck/trim-changelog

Move entries older than last year to changelog-old
[JENKINS-19559] - Noting fixes in #1124 (jenkins-1.553)

Signed-off-by: Oleg Nenashev <o.v.nenashev@gmail.com>
Merge branch 'master' of git://github.com/jenkinsci/jenkins
Noting JENKINS-18654 in 1.524
1197e0c required mocking Item.getName().
MockFolderTest.moving pointed out a refinement to 1197e0c: list folders, if included, before their contents.
Merge commit '78dcd063da55ed725c99165686b14b180d03108f'
Link to 'Building Jenkins' page from text file
Merge pull request #1274 from kevinburke/building-link

Link to 'Building Jenkins' page from text file
[FIXED JENKINS-23410]

Integrated the fix made in winp 1.20.
[JENKINS-21631] - Don't fail with NPE if the PeepholePermalink cache contains the non-numeric value.

Actually, the change just prevents symptoms. There should be an error somewhere else.

Signed-off-by: Oleg Nenashev <o.v.nenashev@gmail.com>
Merge branch 'JENKINS-21631' of github.com:synopsys-arc-oss/jenkins