[JENKINS-54136] Use per-trial correlation IDs

[JENKINS-54135] Fix concurrency bug in languages telemetry

[JENKINS-54137] Do not submit "empty" telemetry

Fix Executor Javadoc for getDisplayName()

SlaveComputer.getRetentionStrategy mistake led to launches of unused agent JVMs

Fixing a synchronization bug in StaplerDispatches.traces

SlaveComputer.getRetentionStrategy was using Always when there was no node, leading to launches of unused agent JVMs.

[JENKINS-53462] Jenkins websites use non-trusted 'submit' event to start form submission when current browser is Firefox

Add localization for time days

* Collect information on Accept-Language header values

* Skip null values

* Address review feedback, do not record while disabled

* Address FindBugs problem

* Add telemetry for Stapler dispatches

* Add TODO

* Released version of Stapler

Adapt to stapler/stapler#149

warn user when deprecated Secret#toString() is being used

Signed-off-by: NNicolas De Loof <nicolas.deloof@gmail.com>

[JENKINS-53462] Use a workaround to submit the form with a trusted event. No comments on the underlying insanity of hudson-behavior.

[JENKINS-51805] - Winstone 5.1: Update Jetty to 9.4.12 in order to pick up fixes towards Java 11 support

The properties file naively assumed that leading spaces would be honored.
-- They are not. To get some indentation, one needs to escape a space first.

Further, for no particular reason, the last paragraph had a hard wrap.

Finally, since this commit has to reindent the entire block, fix the alignment of the `:`s
for most of the options.
(-auth is a mess and should be rewritten)