Describe the bug

Minor bug involving passing a set as a kwarg to the msg method-- the set is correctly identified as an iterable, but is then presumed to be subscriptable in subsequent operations.

https://github.com/evennia/evennia/blob/574d7fbd4f65cae60c534fe592803057d452ed7b/evennia/server/sessionhandler.py#L252-L262

This does not work on set objects.

self.msg(locks=se

A production environment is triggering the exception "Error Message: TypeError: Cannot read property 'insertBefore' of null".

This seems to happen on the admin interface on the url: "/#/admin/questionnaires" in relation to $scope.triggerFieldDialog

The setup is using version 3.0.2

In docs/customization.py (https://github.com/brettcannon/gidgethub/blob/bdd98606438a311e2d16189222c381b0eda4547e/docs/customization.py#L2), we use PyClassmember, which is being deprecated and will be removed in Sphinx 4.0.

It would be great to address that.

Additionally, Sphinx 2.1 supports async and await keywords: https://github.com/sphinx-doc/sphinx/pull/6295/files

I have to guess, given YT Music, and the fact that YouTube has categories, we can determine whether the video is actually a song. If it is, maybe we could use the headphone emoji, or a music (♫ / ♪) symbol to show it as such in the channel?