Update documentation to XmlBeans 4.0.0.
Add download links for 4.0.0.
Unify documentation - move it from xmlbeans/docs to site/src/.../guide
add source code layout
fix site links.
fix javadocs links.

git-svn-id: https://svn.apache.org/repos/asf/xmlbeans/trunk@1882605 13f79535-47bb-0310-9956-ffa450edef68
20 files changed