Update ClassLoaderFilesResourcePatternResolver to support servlet
resources when it's being used with a WebApplicationContext.

Prior to commit 918e122d a `ResourceLoader` was not added to the
`ApplicationContext`, meaning that servlet resources could be found by
virtue of the protected `getResourceByPath()` method. Following commit
918e122d, the context `ResourceLoader` is set, meaning that all calls
to `getResource` delegate to the `ResourceLoader` and the
`ApplicationContext` methods are not invoked. Since the devtools
`ResourceLoader` wasn't Servlet aware, servlet resources could not
be found.

Fixes gh-7752

This commit moves the `MultiMetricRepository` implementation from
`InMemoryMetricRepository` to `InMemoryMultiMetricRepository`. Both
implementations can share the same underlying store (and are for backward
compatible reasons).

The side effect is that `reset` now works as expected for a group.

Closes gh-7687

This commit allows to define `server.port` in a non-embedded web
environment. Previously, `server.port` would have been set to `-1`
regardless.

Closes gh-7353

Closes gh-7771

Add a Log4J2 `ConfigurationFactory` that is always applied so that the
"No log4j2 configuration file found" error message does not appear.

Although the message was harmless it was quite annoying to Spring Boot
users who could safely omit the file.

Fixes gh-4809

Update Log4J2 configurations to respect `FILE_LOG_PATTERN` and
`CONSOLE_LOG_PATTERN` system properties. These system properties are
set by `LoggingSystemProperties` from `logging.pattern.file` and
`logging.pattern.console` properties in the Spring Environment.

Fixes gh-7757

Consistently use the simple name for ObjectProvider parameter and
field names. For example:

  `ObjectProvider<Something> something`

rather than

  `ObjectProvider<Something> somethingProvider`

* pr/7741:
  Notify BuildContext of changed build-info file

Update Maven plugin to inform the BuildContext when changes are made to
the `build-info` file. Prior to this commit Eclipse could continually
trigger refreshes whenever "Refresh using native hooks or polling" was
enabled and the file was written to `src/main/resources`.

Closes gh-7741

* pr/7737:
  Improve Cassandra sample README documentation

Update the README file in `spring-boot-sample-data-cassandra` with
details of how to setup the keyspace and create the tables.

Closes gh-7737

* pr/7769:
  Fix typo in "you IDE"

Change "you IDE" to "your IDE".

Closes gh-7769

Add a simple test to show that basic serving of `/public` resources
works with devtoos.

See gh-7752

Closes gh-7569

See gh-7763

* pr/7763:
  Upgrade to Jersey 2.25

Closes gh-7763

* pr/7765:
  Changed "right the way" to "right away"

Closes gh-7765