AttributeType (Scalar). Also enable parsing of deprecated DataStructure
tag, synonym of DataItem.

Eliminate getRealPath calls which are expensive and not necessary in many cases
Parse XML node content only when necessary (parsing arrays)
Fix cases where copies were made of strings instead of using references
Use "map.insert()" rather than "map[] =" when adding properties to map

Using statements have been added to XdmfSharedPtr.hpp. All used of
boost::shared_ptr and boost::shared_dynamic_cast have been replaced
by shared_ptr and shared_dynamic_cast. Slight modification to XdmfCore.i
to get swig wrapping working again.

Hopefully this will become a standard style for Xdmf development.
All spaces - 80 character line wrapping.

ENH: Get equality functions working again, but keep it in the SWIG file rather the polluting the C++.

Added testing for this for both languages as well. In Java
since you are not allowed to overwrite operators, we just
ignore the warning and overwrite .equals. In Python, we
overwrite the operator.

ENH: Fix Absolute/Relative path issues when reading and writing from separate directories.  Modify XML attributes to be less verbose e.g. (AttributeType --> Type).  Separate XdmfGridCollection from XdmfGrid at the XdmfDomain level.

ENH: Modify ItemProperties to use shared pointers like the rest of Xdmf.  Modify swig wrapping to correctly
handle both non const and const shared pointers.

ENH: Add XdmfItemProperty to genericize properties attached to XdmfItems.  Add a pure virtual getItemProperties() method
to XdmfItem to force children to implement a way to retrieve properties.

unnecessarily duplicated functionality.