Update reference documentation source to use consistent attribute names
and fix a few formatting issues.

Fixup ignore logic in `EndpointRequest`.

See gh-18012

Closes gh-18023

Closes gh-18002

Closes gh-18022

Update the reference documentation so that "Web Application Conditions"
also covers reactive contexts.

Closes gh-18005

Closes gh-18021

Fix caching issues in `ApplicationContextRequestMatcher` and allow
subclasses to ignore an application context entirely. Update existing
matcher implementations so that they deal with the management context
correctly.

Prior to this commit, the `ApplicationContextRequestMatcher` would
return a context cached from the first request. It also didn't
provide any way to ignore a context. This meant that if the user was
running the management server on a different port the matching results
could be inconsistent depending on if the first request arrived on
the regular context or the management context. It also meant that we
could not distinguish between the regular context and the management
context when matching.

Closes gh-18012

* gh-18014:
  Upgrade to jOOQ 3.12.0

Closes gh-18014

See gh-18014

Closes gh-18016

* gh-18015:
  Remove reference to non-existent --edit option in CLI docs

Closes gh-18015

See gh-18015

* gh-17993:
  Polish "Auto-configure Flyway with JavaMigration beans"
  Auto-configure Flyway with JavaMigration beans

Closes gh-17993

See gh-17993

See gh-17993

* gh-17997:
  Polish "Upgrade to Flyway 6.0.1"
  Upgrade to Flyway 6.0.1

Closes gh-17997

See gh-17997

See gh-17997

Restore the blank line at the end of `executable-jar-format.adoc`
which appears to be required.

See gh-18007

Delete file accidentally added during merge.

See gh-18007

See gh-18007

Closes gh-18007

Update reference documentation to use one sentence per line formatting
as recommended by the Asciidoctor team.

Closes gh-12445

Closes gh-17965

Closes gh-17996

* gh-17976:
  Use exec when launching the JVM in CLI's shell script

Closes gh-17976

Previously, when the Spring Boot CLI ran the Java command line for an
application it did a straight invocation which suppressed propagation of
signals to the JVM in certain circumstances (e.g within Docker containers).

This change prepends the command with exec which causes the Java process to
replace the script process in a shell ensuring that signals are propagated to
the Java process without suppression.

See gh-17976
Signed-off-by: Ben Hale <bhale@pivotal.io>

* gh-17991:
  Polish "Improve handling of non-standard status codes in RestTemplate metrics"
  Improve handling of non-standard status codes in RestTemplate metrics

Closes gh-17991

See gh-17991

See gh-17991

Closes gh-17995

* gh-17984:
  Test the Gradle Plugin against Gradle 5.6.1

Closes gh-17984

See gh-17984

Closes gh-17984

Closes gh-17994