- immediately show chat box (sometimes fetching features takes long)
- add timeout for fetching features
- don't register scroll handler twice for chat rooms.

after the cached messages have been fetched.

when the room features change.

Builds are now themselves UMD modules, so they could be `require`'d like any
other AMD module or they can still be used as old ES5 modules with globals.

Additionally the build is now closured, so that the almond API doesn't pollute
the global context with `define` or `require`. This does however mean that
`require` can no longer be used outside of the build (unless requirej.s is
included directly.

Builds are now themselves UMD modules, so they could be `require`'d like any
other AMD module or they can still be used as old ES5 modules with globals.

Additionally the build is now closured, so that the almond API doesn't pollute
the global context with `define` or `require`. This does however mean that
`require` can no longer be used outside of the build (unless requirej.s is
included directly.

https://greenkeeper.io/

Fixes #620

Also, don't query for MAM messages if the chat room doesn't support it.

allow_non_roster_messaging is false.