relax SVN archive

Added the structural information to the XML results file.

Docstring improvements.

The hybrid element is no longer returned.

Shifted the hybridisation info from the global element to its own element.

Shifted all the variables of PipeContainer into the 'global' element.

The 'type' variable is now initialised within the __init__ method.

Added the 'hybrid_pipes' object to the XML document as this will eventually only be a list of str.

Updated the fill_object_contents() function to handle the __mod_attr__ list and skip all _* names.

The diffusion tensor info is now placed into the XML file.

Converted the mod_attr object into a class variable.