Before this change bean scopes chapter in Spring reference documentation
had a note which mentioned that creating a scoped proxy for singleton-
or prototype-scoped beans will throw BeanCreationException.

This is no longer the case and this change removes the mentioned note.

Issue: SPR-7940

Problems

 - Eliminate — in favor of —

   — was causing 'no such entity' errors during docbook
   processing; — produces the equivalent output.

 - Fix column issues in appendices

   column counts were set to 3, when they are in fact 4. This passed
   under DocBook 4 and Spring Build for unknown reasons, but caused a
   hard stop under DocBook 5 and the docbook-reference-plugin.

 - Add jdbc callout section in docbook 5-friendly style

   use <co/> tags as advertised in DocBook documentation.

 - Set correct widths for PDF ref doc images

   images were rendering larger than the PDF page; just set all to
   width=400 and everything looks good.

Polish

 - Update reference doc copyright to 2012

 - Remove "work-in-progress" language from ref docs

 - Update maven URLs to repo.springsource.org

 - Update javadoc urls from 3.0.x/javadoc-api => current/api

 - Replace hardcoded "3.1" with ${version} in ref doc

It was determined (through painful trial and error) that after the
upgrade to DocBook 5 and the gradle-docbook-reference plugin, that
<emphasis> elements embedded within <programlisting> elements causes
NullPointerExceptions during processing.

This change eliminates these <emphasis> elements to work around the
problem. This means a slight degradation in presentation for the
affected areas of the reference documentation. After some research,
it is not clear what other workarounds may be possible that leave
the text actually emphasized.

For compatibility with Gradle docbook-reference-plugin, which cannot
handle DocBook 4.

This change eliminates the spring-framework-reference subproject, moving
these sources into the root project's own src directory.

This makes sense because the reference docs span all submodules, and
also because api Javadoc is created at the root project level as well.
This means that both api and reference documentation output will now
reside in the root project's 'build' directory. This is more consistent
and easy to discover.

Issue: SPR-8591

All <section/> elements in beans.xml >=~ 500 lines have been broken out
into separate documents with DOCTYPE 'section'. This refactoring makes
working with these files much easier in wysiwyg editors (namely
oXygen Author).

For consistency, this same refactoring should be applied to all other
chapters much larger than 1500 lines, such as aop.xml (3861), mvc.xml
(3466), jdbc.xml (3042), and so on.

beans.xml and the new section files have also been formatted for
consistency and to avoid whitespace diffs as much as possible into the
future.