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boost::shared_ptr and boost::shared_dynamic_cast have been replaced
by shared_ptr and shared_dynamic_cast.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.

Added documentation to several methods. Modified Doxygen configuration file to
correctly process macros (tested using Doxygen 1.7.1). Correctly format
documentation to 80 characters per line.

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

ENH: Rename all subclasses of XdmfGrid to more syntactically friendly names: i.e. XdmfGridUnstructured to XdmfUnstructuredGrid.

ENH: Added XdmfGridUnstructured and turned XdmfGrid into an abstract base class for all grids (both structured and unstructured).  Modified a bunch of utils and other classes
to fit this new hierarchy.

The macros
XDMF_CHILDREN and XDMF_CHILDREN_IMPLEMENTATION

add capabilities to add and remove children by index or property from a parent item.  This simplifies the code
as the same insert() getChild() calls were used throughout the code.

ENH: Change some method names in XdmfArray to be clearer and less verbose.  Modify files for documentation clarity.  Modify some minor things to prevent -Wall warnings in gcc.  Add python install rules and rpathing.

ENH: Revert back to XdmfGridCollection inheriting from XdmfGrid - we want the flexibility to be able to add global sets (might be necessary for dft work).

ENH: Remove XdmfGrid inheritance from XdmfGridCollection.  If there is a need for Sets/Attributes at the "global" collection level then we can deal with it in the future.

ENH: Commit Ken Renard's patches modifying populateItem and XdmfCoreReader to support some xpath functionality for backwards compatibility.

ENH: Make XdmfGridCollection inherit from XdmfGrid and XdmfDomain, since it is really a unity of the two classes.  Modify some details in ItemFactory / Reader.

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.

destructors to be publicly accessible.  Modify tests to work with new wrapping.

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.

to write out the Xdmf graph.  Modify some random include statements for style.

ENH: Add pure virtual getItemTag method to XdmfItem working to return the tag (same as in XML terminology) for the specific item.

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.

ENH: Create a generic XdmfVisitor class and move writing operations to XdmfWriter.  Incorporate Loki library to perform asymmetric visitor operation (allows customizable behavior for eventual Xdmf / NetDMF library split).  Modify Loki
Visitor to work happily with boost::shared_ptr and modify swig wrapping to properly handle boost::shared_ptr inheritance.

ENH: Rename write() operation to accept() which is more consistent for the Visitor pattern.  Also, we can
do much more to our Xdmf graph structure than just write it using Visitor operations.

unnecessarily duplicated functionality.

ENH: Split visitor operation into a visit and a traverse operation so that logic of how to traverse the xdmf graph is kept with xdmf objects rather than the visitor.  The visitor calls this function rather than relying on its own logic.