Issue: SPR-12847

Introduces an AbstractXlsView and dedicated subclasses for POI's xmlx support.
Deprecates the traditional AbstractExcelView which is based on pre POI 3.5 API.

Issue: SPR-6898

The `javadoc-baseurl` asciidoctor attribute is now externalized
(i.e. not included directly in the document anymore).

This allows to properly render javadoc links in single pages, whereas
those URLs were previoulsy only supported in the single page version.

Issue: SPR-12209

We use AspectJ 1.9.0.BETA-1 for the ajc task now and exclude spring-oxm test compilation when running on JDK 9.

Issue: SPR-12549

Core and Web chapters are important chapters in the Spring Framework
reference documentation, and splitting them in multiple files will
help to evolve the documentation while not creating too many files.

Issue: SPR-12309

Upgrade to asciidoctor-gradle-plugin version 1.5.2.
Various syntax fixes in the index.adoc reference documentation.

Latest dependency updates (HttpClient 4.4, TestNG 6.8.21, SnakeYAML 1.15, FreeMarker 2.3.22, JRuby 1.7.19, JAMon 2.81, JiBX 1.2.6, XMLUnit 1.6, JsonPath 1.2)

Revert cdc04e55 now that animal sniffer 1.1.4 is available.

Issue: SPR-12766

Issue: SPR-12755

Animal Sniffer 1.11 fails against XStream 1.4.8 due to classes with 1.8 bytecode level.
Animal Sniffer 1.14 will finally include ASM 5.0.3 for proper 1.8 bytecode support.

Deprecated CommonsPoolTargetSource (supporting commons pool 1.5+) in
favor of CommonsPool2TargetSource with a similar contract.

Commons Pool 2.x uses object equality while Commons Pool 1.x used
identity equality. This clearly means that Commons Pool 2 behaves
differently if several instances having the same identity according to
their `Object#equals(Object)` method are managed in the same pool. To
provide a smooth upgrade, a backward-compatible pool is created by
default; use `setUseObjectEquality(boolean)` if you need the standard
Commons Pool 2.x behavior.

Issue: SPR-12532

Issue: SPR-11803

Jasper Reports’ transitive dependency on spring-context (via
castor-xml which is a new dependency in 6.0.3) was being mapped by
Gradle to a dependency on the spring-context project. For reasons that
I do not fully understand this was causing -source and -javadoc jars
to be added to the project's compile classpath which is used by the
Animal Sniffer Ant task. When the task runs these jars do not exist
which causes it to fail. This commit fixes the problem by adding an
exclusion of org.springframework:spring-context to the Jasper Reports
dependencies in spring-context-support and spring-webmvc.

Modules (well-known or user provided) registration is now performed
first in order to allow their configuration to be customized by more
specific ones like custom serializers or deserializers.

Issue: SPR-12634

Issue: SPR-11934

Issue: SPR-12511