* pr/5067:
  Fix typos

Closes gh-5067

Spring Boot fires event very early in the application lifecycle and we
should make crystal clear that a regular `@Bean` registration cannot be
used to register a listener on them.

Closes gh-5061

Ensure that JarFile caches are cleared once the ApplicationContext has
loaded. Caches are cleared manually with the assumption that no
further class loading is likely.

Closes gh-4882

Refactor `spring-boot-loader` to reduce the amount of memory required
to load fat & exploded jars. Jar files now no longer store a full list
of entry data records, but instead use an array of entry name hashes.

Since ClassLoaders often ask each JAR if they contain a particular
entry (and mostly they do not), the hash array provides a quick way to
deal with misses. Only when a hash does exist is data actually loaded
from the underlying file.

In addition to the JarFile changes, the Archive abstraction has also
been updated to reduce memory consumption.

See gh-4882

Remove the use of JDK loggers in Launcher and PropertiesLauncher to
ensure allow the custom Log4j2 `LogManager` to be used with Spring Boot
applications.

Fixes gh-3815

Update SpringApplication to allow classes loaded from spring.factories
to be package private.

Fixes gh-5043

Add SharedMetadataReaderFactoryContextInitializer to ensure that a
shared caching MetadataReaderFactory is used between configuration
classes and auto-configure sorting.

Fixes gh-4993

* contributor_covenant:
  Add contributor covenant

Closes gh-4914

This commit enables the use of // @formatter:off and // @formatter:on
to surround lines of code that should not be formatted. It also adds
a code template that can be used to quickly wrap the selected lines
of text with the off and on comments.

Closes gh-5050

* pr/5026:
  Add cloudant-spring-boot-starter reference

Closes gh-5026

Closes gh-5041

jetty-jndi is no longer shipped by default as of 2b2e21db but one test
checking for this wasn't updated properly.

* pr/4411:
  Update copyright header
  Remove closure-execution from OptionHandler

It seems that the code for executing a groovy closure from the
OptionHandler is never executed and therefore not needed.

Removing the code gives the benefit that the Groovy-classes are not
needed if someone else wants to use the spring-boot-cli infrastructure to
run his own cli interface.

Closes gh-4411

Closes gh-4479

Closes gh-4482

Closes gh-4490

Our Investigations show that JNDI lookup is quite costly on Jetty and it
was enabled by default while embedded tomcat does not. This commit
excludes `jetty-jndi` to align the behavior with Tomcat.

If you are relying on JNDI, the `jetty-jndi` should simply be added in
your project.

Closes gh-4710

The `DataSource` auto-configuration in Spring Boot supports two modes:
regular pooled DataSource and embedded database (via the
`EmbeddedDatabase` infrastructure provided by `spring-jdbc`. These were
previously named `NonEmbedded` and `Embedded` respectively.

This commit clarifies those mode and in particular that a pooled
`DataSource` can also handle an embedded database.

Closes gh-4634

* pr/5028:
  Added dependency for jackson-datatype-json-org

Closes gh-5028

Introduce dedicate method to determine the actual value to use based on
the configuration and the environment.

Closes gh-1436

* pr/4574:
  Polish contribution
  Support for SendGrid ApiKey

Closes gh-4574

See gh-4574

* pr/4590:
  Polish contribution
  Add Thymeleaf's Java8TimeDialect

Closes gh-4590

Closes gh-4576

Closes gh-4496

Closes gh-5014