Fix CLI `omero group perms` subcommmand

Propagate the recent changes made to the group arguments using --id/--name
options to the perms() method using parse_groupid() to return the group and
group identifier.
Fix type check when passing omero.model.ImageI() object
Add support for big image export as an OME-TIFF file

- Initialize an increment INC variable to the value specified in
components/blitz/src/ome/services/blitz/impl/ExporterI.java
- Split the data read into chunks of size INC
- Add logging and console display for big images download
Merge pull request #1352 from sbesson/matlab_exporter

OMERO.matlab: fix OME-TIFF export for large images
Merge pull request #1349 from sbesson/11289_cli_perms

Fix CLI `omero group perms` subcommmand