Fix sessions.py header
Add CLI/API for passing sudo parameter
sessions.py: Add call to createSessionWithTimeouts
Fix empty string bugs in SessionManagerImpl

Probably since the move to Ice, null strings in the
Principal object have been converted to empty strings
which have failed the various tests for setting defaults.
Record 'omero.sudo' in session file
Filter inactivate users from 'omero user email' (Fix #12024)
Use temp/rename for config.xml writing (Fix #12002)
Prevent save_on_close from omeroweb/settings.py (See #12002)
Fix flake8 in user.py
Fix unit test test_sess.py
Add **kwargs to MockConfigXml
Fix flake8 failures in gateway
Fix flake8 warnings in gateway
Fix typo and broken import
Add test_login.py for CLI
Improve `bin/omero sessions help`
Remove unused 'def sudo'
Improve login help incl. `-sudo`

Previously, `bin/omero sessions login -h` and
`bin/omero login -h` differed in their help
text. Now they match and the most basic uses
are (briefly) listed.
Fix flake8 warnings
Fix test_config.py failure

Rather than considering all non-default environments
as failures on read-only, only consider it a failure
when read-only was not *explicitly* requested.