Ensure that identity request variables are UTF-8 encoded

It is critical that the server recieves UTF-8 encoded strings and not
`unicode` instances.  Passing such instances blindly to the `str()`
constructor will result in a `UnicodeDecodeError` being raised.
Rename 'Launch Full Viewer' button
Rdef menu 'Set Owner's' moved to last item
Don't allow zoom < 0
Z/T sliders red -> white
Add Full-range, Imported etc buttons to Image viewer
Test case for proper unicode encoding when using gateway
Merge pull request #3041 from will-moore/preview_panel_3

Preview panel 3
Fix flake8 errors
Merge pull request #2994 from chris-allan/fix-password-encoding

Ensure that identity request variables are UTF-8 encoded
Update develop submodules

Repository: openmicroscopy/openmicroscopy
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Repository: openmicroscopy/bioformats
Updating 0819d22..32c7be8
Previously merged:
  # PR 1342 joshmoore 'Catch all exceptions on loadMemo'
  # PR 1340 joshmoore 'kryo: update to 2.24.0 with shading changes (see #10852)'
  # PR 1331 rleigh-dundee 'C++: Add FormatWriter interface'
  # PR 1335 melissalinkert 'ND2: prevent NumberFormatExceptions when parsing text data (rebased onto develop)'
  # PR 1324 melissalinkert 'Deltavision: conditionally ignore stage position values of 0'
  # PR 1317 melissalinkert 'Gatan: fix physical dimension parsing when the Z size is missing'

Repository: ome/scripts
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Repository: openmicroscopy/ome-documentation
Updating 01a91b2..9f72455
Previously merged:
  # PR 987 snoopycrimecop 'Update auto-generated properties'
  # PR 984 aleksandra-tarkowska 'adding support for django directives'

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