Modify joinSession.
Remove tabs and space.
Post an event to discard viewer.

Event posted when the re could not be reloaded.
Create new session if failed to join.
handle differently dns for testing.
Print out error.
Clean up and remove unused code.
Make sure System users cannot be removed from System group.
Clarifications thanks to @bpindelski
Add/remove user and do not display user group.
Reset Image.archived flag where necessary (Fix #11810)

During the upgrade testing of nightshade for 5.0.0-beta2-rc3,
images were found which had incorrect `archived`. This won't
prevent the flags from being mis-set again, but for starting
with `5.0__0` it will at least be consistent.
Fix Tag removal contentType: See #11821
Fix Basket action contentType: See #11819
Remove contentType: from deleteItem - just in case
img.getProject() no Errors if multiple parents. See #11807
Set global min/max according to pixel type. (see #11840)
Check early if network I/F is up or loopback
Refactor test_tag using pytest.mark.parametrize

    Parametrize tag creation, tagset creation and tag linking
Enforce long as type of tag id arguments
Fix integration test for tag/tagset creation with no description