Added support for dragging target on WPF windows and building simple
xpath statements. Fixed some null results in native library and
increased performance of enumerating wpf windows. Still need to tweak
filters for picking up Silverlight handles too.
The WpfBridge native library can now enumerate all WPF and Silverlight
Windows and list them in Synthuse. Still need to add a method to
connect the Drag Target to locate the WPF window.
