Closes gh-4304

Closes gh-4314

Previously, OrderedRequestContextFilter was ordered such that it
ran after Spring Security's Filter. This meant that the request
context was unavailable to any Filters in Spring Security's Filter
chain. Specifically, this caused a failure when using @EnableOAuth2Sso
as OAuth2ClientAuthenticationProcessingFilter, which is added to
Spring Security's Filter chain would be unable to use the
request-scoped bean upon which it depends.

This commit updates the order of OrderedRequestContextFilter so that
the request context is set up before Spring Security's Filter runs.
The tests for SampleGitHubApplication have been updated to use
TestRestTemplate rather than MockMvc. This is necessary as the latter,
via ServletTestExecutionListener, automatically populates the request
context holder, masking the fact that the request context filter was
setting it up too late.

Closes gh-4270

Closes gh-3010

Closes gh-3864

If a filter is registered in `web.xml` with no `dispatcher` element, the
spec states that it should have the `REQUEST` dispatcher type only.

As we are adding more dispatcher types by default, it can be surprising
for users migrating from a `web.xml` based  web app. The documentation
has now an explicit note about this.

Closes gh-2689

Closes gh-4311

Better describe what Spring Boot offers with regards to dependency
management and how it translates in Maven and Gradle.

Closes gh-2580
Closes gh-3695

* pr/4309:
  Polish contribution
  Polish docs

I don't think we want to keep this on a single line.

Closes gh-4309

See gh-4309

Closes gh-4159

Closes gh-3438

Closes gh-4153

Closes gh-4293

Previously, NamePatternFilter looked for “*”, “$”, “^”, or “+” when
trying to identify a string as being a regular expression. This meant
that it missed the use of a character class ([a-z], for example). This
commit adds “[“} to the list of characters that are considered to be
part of a regular expression.

Closes gh-4233

Closes gh-4193

See gh-4263

Closes gh-4263

Closes gh-4257

Make sure that the remote URL does not contain a trailing slash.

Closes gh-4297

It doesn't appear to be in Maven Central and it's breaking the eclipse
setup.

As the Windows service support is not related at all to the executable
jar support it needs to be in a separate location.

* pr/4272:
  Fix broken links

Closes gh-4272

Improve the initial PR to include a filtering of the profiles that were
already enabled via the `spring.profiles.active` property.

Also add more tests to prove that each profile is loaded only once
now.

Closes gh-4273

The problem fixed here is that the Loader keeps track of the profiles it
is going to look at for loading files, but ignores any that were already
active in the Environment if the listener is called initially with
spring.profiles.active not empty.

Closes gh-4261

Closes gh-4268

* pr/4265:
  Fix error messages

Closes gh-4265

Closes gh-4262

Previously, the `PORTFILE` system property was not checked if the
`EmbeddedServerPortFileWriter` was created using the default constructor.

This had the effect to prevent overriding of the port file when this
listener is created without any file or via `META-INF/spring.factories`.

Closes gh-4254