* [JENKINS-49737] - Update Extras Executable WAR to 1.38

* Use the released version of Extras Executable War 1.38

(cherry picked from commit fa54b49f)

(cherry picked part of commit fcae9bb5)

* Fix a race condition in Util.loadFile()

If the file is deleted in between when its existence is checked and the
file is opened for reading, then the method will fail to return an empty
string.

* Switch to using FileUtils.readFileToString()

(cherry picked from commit aaae71af)

If a subclass was serialized (default java serialization) then the
changes do push down the method to the interface would break
deserialisation when in reality the classes are still compatable.

Restoring the compatability by hard coding the serialVersionUID to what
it was before the change.

(cherry picked from commit dcf22ca8)

(cherry picked from commit ff345324)

* Don't forget estimated duration of asynchronous jobs.

When jobs are executed, the estimated duration is calculated, memorized
and reseted when the job is finished.

But when the job is executed asynchronously (e.g. as for pipeline
scripts), the execution is just triggered. Therefore the estimated
duration should remain - and not be reseted after triggering.

JENKINS-48821: Time remaining for all pipeline jobs is N/A
JENKINS-49616: Estimated time remaining NA

* Reset cached estimated duration also when asynchronous job ends.

(cherry picked from commit 3fc39210)

[JENKINS-50056] - Do not copy all build numbers in case of descending search

(cherry picked from commit 62324919)

[JENKINS-29470] - Prevent NPE in AbstractProject.checkout when agent disconnects during the build (#3094)

[JENKINS-29470] - Prevent NPE in AbstractProject.checkout when agent disconnects during the build

(cherry picked from commit b0c5a86a)

(cherry picked from commit 9054e221)

* [JENKINS-49596] - Update Winstone to 4.1.1

* [JENKINS-49596] - Pick 4.1.2 with extended session eviction defaults

(cherry picked from commit 852ecdc5)

(cherry picked from commit e5f61e29)

* [FIX JENKINS-30909] Make sure queue is persisted reliably

* Fix tests on Windows

* Ensure Saver is thread-safe

(cherry picked from commit 72a7529a)

[JENKINS-49634] Wrong escaping of quotes in the Setup Wizard

(cherry picked from commit dcb1bcd5)

[JENKINS-49498]: Fix poorly translated sign-up string (dutch)

(cherry picked from commit 59bfe03e)

[JENKINS-34712] Always show the master node when it is offline

(cherry picked from commit b67a30f8)

(cherry picked from commit 36f7fc0d)

* Fixes for validation

* Fix for an empty agent.nExecutors

(cherry picked from commit 5c8cc459)

(cherry picked from commit 376c6a0a)

(cherry picked from commit 800668ba)

Updated SSHD Module to 2.4 to bundle SSHD Core 1.7.0

* Slave.JnlpJar.getURL did not work in some modes when core had a snapshot dependency on Remoting.

* Starting to implement Channel.Listener.read/write.

* Now obtaining response timing statistics.

* For now, avoiding timestamped snapshots, as it caused problems for #3120 which I have asked for help from @stephenc diagnosing.

* Simplified logging a bit.

* onResponse

* hudson.FilePath$Mkdirs is a lot more readable than hudson.FilePath$13.

* Specific snapshot.

* onJar

* LoggingChannelListener

* remoting.version=3.17

* Making a few test assertions more lenient to adapt to https://github.com/jenkinsci/remoting/pull/247.