Trestle: only set the resolution count if resolutions are unflattened

Conflicts:

	components/bio-formats/src/loci/formats/in/TrestleReader.java
Trestle: fix openBytes' behavior when resolutions are unflattened

Conflicts:

	components/bio-formats/src/loci/formats/in/TrestleReader.java
Trestle: one more fix for unflattened resolutions
Trestle: only parse mask data for non-OME-XML stores
Add missing import
Add a few comments explaining the overlap calculations