Issue: SPR-15885

Issue: SPR-15885

This commit changes the resolveMethod to take a method name as
instrumentation may add additional methods to the test object.

Issue: SPR-15888

This commit ensures that only the HTML version of the reference
documentation is rendered for SNAPSHOT builds. This speeds up
significatly the build.

Issue: SPR-15885

As of Gradle 4.0, project SourceSets can have multiple output
directories (one per programming language).
This commit fixes warnings that are logged when a single output dir
is considered by tasks.

Issue: SPR-15885

This commit applies the Dependency Management Plugin to modules that
require it; right now Spring Framework is importing BOMs for Netty and
Reactor dependencies only.

Instead of applying those BOMs to all modules, they're applied only
where they're needed.

Issue: SPR-15885

The main `build.gradle` file contains now only the common build
infrastructure; all module-specific build configurations have
been moved to their own build file.

Issue: SPR-15885

This commit merges back the "spring-beans-groovy" module into the main
"spring-beans" one. The build is configured so:

* Java and Groovy sources are jointly compiled
* Kotlin sources are compiled after

With this change, the `MergePlugin` is not used anymore in the project
build and therefore is removed.
The `DetectSplitPackagesPlugin` wasn't applied so it's been removed as
well.

Issue: SPR-15885

This commit reorders docs generation (javadoc, asciidoctor) *after*
runing tests for `./gradlew build` commands.

Issue: SPR-15885

Note: this syntax automatically applies the plugin to the root project.
Adding `apply false` in the plugin declaration disables that.

Issue: SPR-15885

With this change, each subproject can configure its
build in a dedicated file like:

```
spring-core/spring-core.gradle
spring-web/spring-web.gradle
```

Issue: SPR-15885

This commit configures Gradle build scans for the Spring Framework
build. Scans aren't performed for every build but can be enabled
with the following:

```
./gradlew build --scan
```

Issue: SPR-15885

Closes gh-1501

Includes general streamlining of dependency declarations with reduced version variables, direct use of EclipseLink 2.7 and its implicit JPA 2.2 dependency in spring-orm, mixed use of Hibernate 5.2.10 and 5.1.10 for integration tests, as well as an upgrade to Jetty 9.4.7 RC0 and a downgrade to Groovy 2.4.12 (since Groovy 2.5 won't be final in time for Spring Framework 5.0).

Issue: SPR-15879
Issue: SPR-15880

Issue: SPR-15673

Issue: SPR-15149

Issue: SPR-15871

Issue: SPR-15872

Issue: SPR-15869

Issue: SPR-15532

Bean-derived null values may still get passed into bean properties and injection points but only if those are declared as non-required. Note that getBean will never return null; a manual bean.equals(null) / "null".equals(bean.toString()) check identifies expected null values now.  This will only ever happen with custom FactoryBeans or factory methods returning null - and since all common cases are handled by autowiring or bean property values in bean definitions, there should be no need to ever manually check for such a null value received from getBean.

Issue: SPR-15829

Issue: SPR-15149

Refer to both Servlet and reactive stacks in web.adoc
Move web-integration.adoc to the very end
Link in web-flux-functional.adoc
Insert "Spring Web MVC" or "Servlet" prefix in chapter titles

Issue: SPR-15149

Issue: SPR-15869

Includes latest dependency updates (Tomcat 8.5.20, Protobuf 3.4, RxJava 2.1.3, Caffeine 2.5.5)

Issue: SPR-15870

Issue: SPR-15858

Issue: SPR-15542

Issue: SPR-15867

Instead of always using the default JSON mime types

Issue: SPR-15860

Issue: SPR-15852

This commit restores and existing redirectedUrl and forwardedUrl
methods (simple String comparison) and creates separate
redirectedUrlTemplate and forwardedUrlTemplate methods that expand
and also encode before comparing.

Issue: SPR-15834