Closes gh-22659

Closes gh-22603

See gh-22634

See gh-22634

This commit updates license headers for source files residing in
subpackages named `target`.

Closes gh-22634

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://www.apache.org/licenses/ with 1 occurrences migrated to:
  https://www.apache.org/licenses/ ([https](https://www.apache.org/licenses/) result 200).
* [ ] http://www.apache.org/licenses/LICENSE-2.0 with 6515 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).

See gh-22598

As recommended by RFC 7231, this commit restore using 2 digit days
when formatting dates while still using
DateTimeFormatter.RFC_1123_DATE_TIME for parsing.

Closes gh-22478

This commit updates Jackson2ObjectMapperBuilder in order
to ensure that modules specified via modulesToInstall
eventually override the default ones.

Closes gh-22576

Extend the list of disconnected client errors in HttpWebHandlerAdapter
to include the Reactor Netty AbortedException as well exceptions with
the message "connection reset by peer".

Closes gh-21790

Prior to this commit, documentation for WebJar support referenced the
webjars-locator artifact; however, Spring now uses the
webjars-locator-core artifact.

This commit updates the documentation to reflect this.

Closes gh-22613

This commit changes the UndertowServerHttpResponse to use a
listener-based approach instead of a blocking approach.

Closes gh-22413

* pr/22597:
  Polish "Remove outdated link in documentation"
  Remove outdated link in documentation

Closes gh-22597

See gh-22597

Closes gh-22564

See gh-22577

Prior to this commit, the PDF version of the Spring Reference Manual
contained HTML <strong></strong> tags in code examples due to the fact
that Asciidoctor converts bold formatting (i.e., elements wrapped in
`**` or `*`) within source code blocks into HTML tags even for PDF
rendering.

This commit addresses this issue by removing all bold formatting from
example code blocks.

Closes gh-22577

Closes gh-22522

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed But Review Recommended
These URLs were fixed, but the https status was not OK. However, the https status was the same as the http request or http redirected to an https URL, so they were migrated. Your review is recommended.

* http://quartz-scheduler.org/api/2.2.1/ (301) migrated to:
  https://www.quartz-scheduler.org/api/2.2.1/ ([https](https://quartz-scheduler.org/api/2.2.1/) result 404).

## Fixed Success
These URLs were fixed successfully.

* http://docs.jboss.org/jbossas/javadoc/4.0.5/connector/ migrated to:
  https://docs.jboss.org/jbossas/javadoc/4.0.5/connector/ ([https](https://docs.jboss.org/jbossas/javadoc/4.0.5/connector/) result 200).
* http://docs.jboss.org/jbossas/javadoc/7.1.2.Final/ migrated to:
  https://docs.jboss.org/jbossas/javadoc/7.1.2.Final/ ([https](https://docs.jboss.org/jbossas/javadoc/7.1.2.Final/) result 200).
* http://docs.oracle.com/cd/E13222_01/wls/docs90/javadocs/ migrated to:
  https://docs.oracle.com/cd/E13222_01/wls/docs90/javadocs/ ([https](https://docs.oracle.com/cd/E13222_01/wls/docs90/javadocs/) result 200).
* http://docs.oracle.com/javaee/7/api/ migrated to:
  https://docs.oracle.com/javaee/7/api/ ([https](https://docs.oracle.com/javaee/7/api/) result 200).
* http://docs.oracle.com/javase/8/docs/api/ migrated to:
  https://docs.oracle.com/javase/8/docs/api/ ([https](https://docs.oracle.com/javase/8/docs/api/) result 200).
* http://fasterxml.github.io/jackson-core/javadoc/2.9/ migrated to:
  https://fasterxml.github.io/jackson-core/javadoc/2.9/ ([https](https://fasterxml.github.io/jackson-core/javadoc/2.9/) result 200).
* http://fasterxml.github.io/jackson-databind/javadoc/2.9/ migrated to:
  https://fasterxml.github.io/jackson-databind/javadoc/2.9/ ([https](https://fasterxml.github.io/jackson-databind/javadoc/2.9/) result 200).
* http://fasterxml.github.io/jackson-dataformat-xml/javadoc/2.9/ migrated to:
  https://fasterxml.github.io/jackson-dataformat-xml/javadoc/2.9/ ([https](https://fasterxml.github.io/jackson-dataformat-xml/javadoc/2.9/) result 200).
* http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/ migrated to:
  https://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/ ([https](https://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/) result 200).
* http://issues.gradle.org/browse/GRADLE-1116 migrated to:
  https://issues.gradle.org/browse/GRADLE-1116 ([https](https://issues.gradle.org/browse/GRADLE-1116) result 200).
* http://projectreactor.io/docs/core/release/api/ migrated to:
  https://projectreactor.io/docs/core/release/api/ ([https](https://projectreactor.io/docs/core/release/api/) result 200).
* http://tiles.apache.org/framework/apidocs/ migrated to:
  https://tiles.apache.org/framework/apidocs/ ([https](https://tiles.apache.org/framework/apidocs/) result 200).
* http://tiles.apache.org/tiles-request/apidocs/ migrated to:
  https://tiles.apache.org/tiles-request/apidocs/ ([https](https://tiles.apache.org/tiles-request/apidocs/) result 200).
* http://www.apache.org/licenses/LICENSE-2.0 migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).
* http://www.eclipse.org/aspectj/doc/released/aspectj5rt-api/ migrated to:
  https://www.eclipse.org/aspectj/doc/released/aspectj5rt-api/ ([https](https://www.eclipse.org/aspectj/doc/released/aspectj5rt-api/) result 200).
* http://www.reactive-streams.org/reactive-streams-1.0.1-javadoc/ migrated to:
  https://www.reactive-streams.org/reactive-streams-1.0.1-javadoc/ ([https](https://www.reactive-streams.org/reactive-streams-1.0.1-javadoc/) result 200).
* http://docs.spring.io/spring-framework/docs migrated to:
  https://docs.spring.io/spring-framework/docs ([https](https://docs.spring.io/spring-framework/docs) result 301).
* http://glassfish.java.net/nonav/docs/v3/api/ migrated to:
  https://glassfish.java.net/nonav/docs/v3/api/ ([https](https://glassfish.java.net/nonav/docs/v3/api/) result 301).
* http://pic.dhe.ibm.com/infocenter/wasinfo/v7r0/topic/com.ibm.websphere.javadoc.doc/web/apidocs/ migrated to:
  https://pic.dhe.ibm.com/infocenter/wasinfo/v7r0/topic/com.ibm.websphere.javadoc.doc/web/apidocs/ ([https](https://pic.dhe.ibm.com/infocenter/wasinfo/v7r0/topic/com.ibm.websphere.javadoc.doc/web/apidocs/) result 301).
* http://projects.spring.io/spring-framework migrated to:
  https://projects.spring.io/spring-framework ([https](https://projects.spring.io/spring-framework) result 301).
* http://springframework.org/schema migrated to:
  https://springframework.org/schema ([https](https://springframework.org/schema) result 301).
* http://ehcache.org/apidocs/2.10.4 (301) migrated to:
  https://www.ehcache.org/apidocs/2.10.4 ([https](https://ehcache.org/apidocs/2.10.4) result 301).

* pr/22572:
  Polish "Align RdbmsOperation javadoc with jdbcTemplate defaults"
  Align RdbmsOperation javadoc with jdbcTemplate defaults

Closes gh-22572

See gh-22572

Closes gh-22544

See gh-22394

Closes gh-22547

Includes Mockito 2.25, Undertow 2.0.19, OpenPDF 1.2.10, JRuby 9.2.6.

See gh-22504

Closes gh-22504

See gh-22510