Refactoring out XmlSchemaStateMachineNode.Attribute to
XmlSchemaAttrInfo.

This will be needed to separately check if an attribute is a reference,
as set by the XmlSchemaWalker.
Changing XmlSchemaVisitor.onVisitAttribute() to receive a
XmlSchemaAttrInfo instead.
Converting to XmlSchemaAttrInfo in order to carry along whether or not
the attribute is top-level.
Top-levelness is required information.

Cannot delete the XmlSchemaAttrInfo(XmlSchemaAttribute,
XmlSchemaTypeInfo), it is used by the tests.
Adding state machine information to the DomBuilderFromSax.  This will
help identify which attributes are top-level and which are not.
Bug fix: now properly tracking if an attribute is top-level or not.
Fixing the incorrect package name.

Starting documentation of package-info.java.

Will likely need to break this up into further packages.
Moving the state-machine-generation code to a separate package.
Separating everything into two packages:

org.apache.ws.commons.schema.walker:
   This is responsible for walking XML Schemas and XML Documents.

org.apache.ws.commons.schema.docpath:
   This is responsible for building a path through an XML Schema which
represents the XML Document.
Moving DomBuilderFromSax to org.apache.ws.commons.schema.docpath.  This
is more closely tied to forging new a path than walking an existing one.
What am I thinking?  SaxWalkerOverDom belongs in
org.apache.ws.commons.schema.docpath too.
Better documentation of the org.apache.ws.commons.schema.docpath
package.

Restricting access to XmlSchemaElementValidator and
XmlSchemaPathManager, which do not need to be public.
Moving XmlSchemaMultiBaseUriResolver to its intended home.
Adding documentation to DomBuilderFromSax.
Documentation for XmlSchemaElementValidator and
XmlSchemaStateMachineNode.
Documentation for XmlSchemaNamespaceContext.
Documenting XmlSchemaPathFinder.

Changing method name to better explain what the method is doing.
Documentation for XmlSchemaPathNode.
Documentation for XmlSchemaDocumentNode.
Documentation for XmlSchemaStateMachineGenerator.