This is a major change to the /#subscriptions page, converting it to
by a side-by-side list of streams and their settings in an overlay.
There are no new features added/removed, but it's a huge changeset,
because it replaces the old navigation logic and moves the stream
creation modal to appear in the right side of this overlay.
This adds an event listener (by way of delegation) to the
.message_inline_image elements that pops up the overlay and hides it
when the overlay exit is clicked.
Fixes#654.
The find-add-class tool, when in lint mode, verifies that we can
understand all calls to addClass from our JS code.
When in non-lint mode, i.e. verbose mode, the tool prints out a
list of tuples of (fn, class) that we can use as we wish in other
tools.
Brock Whittaker
Steve Howell