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: Modify several utils to take XdmfHDF5Controller as an argument so that they can write data to hdf5 as generated rather than keeping it all in memory.  This is an optional argument.

ENH: Add XdmfExodusReader for reading ExodusII files into Xdmf.  Add ability for XdmfArray::initialize() to take a size value to initialize the array to.

ENH: Rethink XdmfWriter / XdmfCoreWriter distinction and move XdmfSet to XdmfArray conversion in XdmfSet's traverse method.  If conversion is unneeded then do not traverse XdmfSet.

ENH: Make XdmfSet behave like a real std::set.  Modify some writing functionality to make this possible.

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: Modify reading of XdmfArray dimensions to correctly calculate size for multidimensional arrays.

ENH: Modify all filesystem paths used in xdmf to use the absolute real path - aka "canonical path".  Modify tests to ensure this is working.

ENH: Remove getLastWrittenDataSet from HDF5Writer and just get that information from the appropriate HDF5Controller attached to the Array.

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: Clean up XInclude additions.  Verify that writing reading and writing an XPath/XInclude file produces the same file.

ENH: Add XPath writing capabilities to XdmfWriter.  Whenever a duplicate XdmfItem is written to disk, instead of writing it twice, XPath the first.  We will hopefully mirror this behavior when reading in.

ENH: Add XdmfTime and allow it to be attached to XdmfGrid.  Add some convenience functions in XdmfGrid
to get and remove XdmfAttributes and XdmfSets by name.

ENH: Add Mode to XdmfWriter.  Default mode ensures that all heavy data referenced by the XML file being written
exists in a single heavy data file.  A DistributedHeavyData mode can be set to allow heavy data referenced by
the XML file to exist in more than one hdf5 file.

ENH: Add Name property to XdmfArray and accessor functions for getting and setting the name.  If no name is specified it is not written to XML.  Modify test to verify reading and writing is working.

ENH: Modify XdmfWriter to insert XdmfArray content into most recently created child to allow for creation of multiple XdmfArray children.

ENH: Rename get/set ItemProperties for conciseness.  e.g. getAttributeCenter ---> getCenter .  This follows
what is done for XdmfArray (getType).

ENH: Add python wrapping for XdmfUtils and modify some swigisms to get reader working properly in python.

ENH: Allow XdmfArrayType to correctly read old xdmf files containing "NumberType" XML attribute, which is the same as DataType.

ENH: Begin implementing XdmfTopologyConverter.  Fix typo in XdmfArray that incorrectly initialized UInt32() type.