Add 2-Fileset delete tests - both failing

This is the equivalent of what we have in chgrp.py. If a delete is blocked by
2 filesets, both should be returned in the rsp.constraints['Fileset')
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Add function to retrieve plane information from an image
Merge pull request #1197 from will-moore/fileset_display_tweaks_10866

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Merge pull request #1196 from will-moore/test_delete_2_MIFs

Add 2-Fileset delete tests - both failing
Merge pull request #1204 from sbesson/rebased/develop/matlab_planeinfo

OMERO.matlab: Add function to retrieve plane information from an image (rebased onto develop)
Merge pull request #1191 from jburel/import-callback

Import callback
Pass null in event instead of 0 as timeLeft
Update timeLeft field logic in StatusLabel
Add TimeEstimator iface in importer.util
Inject TimeEstimator into uploadFile().
Update JavaDoc on TimeEstimator.
Add TimeEstimatorImpl.