Allow passing image link in the item passed to appendValidatedData.
When passing image link via any of the append* functions, make sure
that create_item_from_text for that pill also adds the image link to
the item created.
This commit does not make any visual change to the current app.
Changes to user_pill.js are necessary to enable user avatars for
pills.
This run_test helper sets up a convention that allows
us to give really short tracebacks for errors, and
eventually we can have more control over running
individual tests. (The latter goal has some
complications, since we often intentionally leak
setup in tests.)
Cynthia Lin
Shubham Padia
Joshua Pan
Steve Howell
Rohitt Vashishtha