Add H5close() statements to clean up pointers.
Add check for existing h5 file to test_matlib_hdf5
Merge branch 'staging' of github.com:crbates/pyne into crbates-staging
Use file access property settings to close all remaining objects

Instead of calling H5close which could break other open hdf5 files just
close the indentifiers for the file that is currently being accessed
using access property list settings.
Merge branch 'staging' of github.com:crbates/pyne into crbates-staging