Change up halContiguousRegions to work w/ preserving structure def
Change up halContiguousRegions to work w/ preserving structure def

Should still work with old "contiguous" definition with the right
options.

glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal,glennhickey/hal