nowplaying.py

Works around API differences in Misskey forks such as Foundkey that result in pretty opaque 500 errors.

I got fed up with one file of nasty spaghetti code so I learned some more Python to refactor it a little prettier.

In the meanwhile I got rid of Mastodon (#2) and Twitter (#3) support because there's no way for me at this point to test (use) them.