Re: [webcomponents] Replace attached/detached callbacks with insertedIntoDocument/removedFromDocument (#362)

I like `connectedToDocument` / `disconnectedFromDocument` better than `inserted` / `removed` because it's more explicit especially if we wanted to add the latter two whenever any ancestor changes in the future.

---
Reply to this email directly or view it on GitHub:
https://github.com/w3c/webcomponents/issues/362#issuecomment-175886802