[FIXED JENKINS-23994] Autocomplete logger names
[FIXED JENKINS-24032] Different message when restart is not supported.
[FIXED JENKINS-24095] Ensure only numExecutors exist when reducing

When reducing the number of executors from M to N, previously it'd
kill all idle executors, and then create executors 0...N-1 unless
they already exist (busy executors).

This can lead to the situation where e.g. executor #5 is busy and
retained, and when setting the number of executors to 3, 0...2 are
created, resulting temporarily having 4 executors.

This change prevents #2 from being created in the example. When #4
is finished, it'll be killed anyway and a new executor #2 created,
so after some time the executor indexes are cleaned up matching
expectations.
[FIXED JENKINS-24614] Broken format string in Hebrew console output
[FIXED JENKINS-24914] Don't block indefinitely every other month
[FIXED JENKINS-6153] Add description for label atoms

The change to descriptionForm.jelly is necessary because JEXL
interprets the previous version as a call to the static method
get(String) of LabelAtom if ${it} is of that type.

Conflicts:
	core/src/main/resources/hudson/model/Label/sidepanel.jelly
[JENKINS-6153] Only show configure link for label atoms

Conflicts:
	core/src/main/resources/hudson/model/Label/sidepanel.jelly
[JENKINS-6153] Move @since comment to getter