Added support for referring to XML elements by shorthand only.

If a controller class defines a namespace with shorthand "x", @Node
and @Attribute annotations can now refer to an element in that namespace
using just the shorthand prefix "x:". In that case the name of the
method or parameter that is annotated is used to look up the element in
the XML.
Refactored the implementation code.

ControllerClass is no more. It's been replaced by a new NamespaceMap
that handle all namespace stuff of the code in the old
ControllerClass. The remaining code has moved to the ControllerMethod
 class.
Removed dead code from ReflectionUtil.