Fixing XML reader/writer for AMR datasets.
Adding new classes vtkXMLUniformGridAMRDataWriter / vtkXMLPUniformGridAMRDataWriter based on vtkXMLHierarchicalBoxDataWriter / vtkXMLPHierarchicalBoxDataWriter to write all types of AMR datasets in VTK XML format. vtkXMLHierarchicalBoxDataWriter and vtkXMLPHierarchicalBoxDataWriter are now simply empty subclasses for backwards compatibility. The XML file format had to be extended to write enough meta-data to support loading of Overlapping AMR datasets correctly. Consequently, the version number was updated to 1.1. Adding vtkXMLUniformGridAMRReader for reading VTK XML files for AMR datasets (overlapping and nonoverlapping). Also added a new test TestAMRXMLIO. vtkXMLUniformGridAMRReader reader v1.1. For older versions, added a converter vtkXMLHierarchicalBoxDataFileConverter (and a test) that converts the xml to the new format. vtkXMLUniformGridAMRReader provides appropriate meta-data in RequestInformation() pass, similar to other AMR reader such as Flash/Enzo. ...