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

The hard-coded URLs in the translation strings should be replaced by variables to ensure they are not different between languages.

Snapweb should support opus. There is a opus branch with a emscripten cross compiled opus library, but it's getting out of sync during playback, maybe the decoding must be done in a thread.

New feature motivation

Today you can choose to sprinkle colors of your different tabs but you can't give the badges different colors.
If I for example want to highlight that there are zero signed documents with a red colored badge I could make that tab pop by using a red badge color.

Example look:

<img width="520" alt="Screenshot 2020-10-29 at 12 48 17" src="https://user-images.githu