Flush cached sort indices when writing to an array attribute.  Closes #137.
Merge branch 'master' of github.com:sandialabs/slycat
Allow integers and ellipses hyperslice arguments in slycat.hdf5.Array.set_data().
Stub-out a new API for storing array attribute data.
Fixing bug where PIModel would not load when rating or category columns were undefined.
Merge branch 'master' into parameter-image-model