Previously, some functions that conceptually belong to the connection needed to be in the Controller, since we didn't have a place to put them.
This fixes that by extending the Connection class in a similar way as we extend the Room class.
It's not obvious at first glance that you can click on the avatar in the
account editor to upload an image. This adds a new button when there is
no image uploaded.
Numerous refinements to the new mobileform setting pages
- Ensure left and right padding at the top level is 0 for mobile
- Centre align the avatar in the account editor page and add tooltip to button
- Fix the bubble/compact mode setting so that it fits when thin, i.e on mobile
- Fix the loading placeholder in device settings
