hdfview

Merge pull request #42 in HDFVIEW/hdfview from ~JHENDERSON/hdfview:feature/ObjectLibraryRewrite to hdfview-3

* commit 'f9fba33fb9861c0071b0d3667c1383aad01a88f2':
  Update all of the object tests to account for Exceptions and OutOfMemoryErrors with Attribute getData
  Update Attribute to properly subclass HObject
  Update MetaDataFormat to MetaDataContainer
  Have Attribute extend HObject
  Move DataFormat to MetaDataFormat