CZI: make sure that SubBlocks are correctly initialized in openBytes

Fixes http://trac.openmicroscopy.org.uk/ome/ticket/11958.

This also fixes an interleaving bug with one of the files in test_images_good.

To test, verify that the file from 11958 and all of the .czi files in test_images_good (and maybe a few from data_repo/from_skyking/zeiss-czi) import correctly into OMERO.  Thumbnails should not be black, the full viewer should open and display a reasonable-looking image, and there should not be a NullPointerException in the Blitz-0.log.