Reworked chapter about hierarchical configurations in user's guide.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601234 13f79535-47bb-0310-9956-ffa450edef68
Extracted a chapter about hierarchical configurations.

It makes sense to separate the information common to all hierarchical
configuration sources from the XML-specific descriptions.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601235 13f79535-47bb-0310-9956-ffa450edef68
Added some more subsections to the chapter for hierarchical configurations.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601236 13f79535-47bb-0310-9956-ffa450edef68
Removed documentation extracted to another chapter from howto_xml.

Also wrote a short introduction.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601237 13f79535-47bb-0310-9956-ffa450edef68
Reworked the sub sections of the XML chapter of the user's guide.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601238 13f79535-47bb-0310-9956-ffa450edef68
Added a subsection with builder parameters for XML configurations.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601239 13f79535-47bb-0310-9956-ffa450edef68
XMLConfiguration no longer implements the EntityResolver interface.

The resolveEntity() method has already been deprecated in the 1.x version.
Entities are now exclusively resolved by an external resolver.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601240 13f79535-47bb-0310-9956-ffa450edef68
XMLConfiguration no longer implements the EntityRegistry interface.

It is now expected that a fully initialized EntityResolver is passed to the
initialization parameters of a configuration builder.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1601241 13f79535-47bb-0310-9956-ffa450edef68