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.
Filter behaves similarly to filter in left sidebar, see PR #684. Added
stream input field to the stream creation modal along with other settings,
for clarity.
Fixes#455, #563.
If a user is not allowed to create new streams, then do not
show the "Create new stream" UI at the top of the settings page.
(imported from commit b97626938d8b612317c2189f7eca0d4bd27fc274)
Tim Abbott
Brock Whittaker
trueskawka
Umair Khan
Waseem Daher
Steve Howell
Allen Rabinovich
Tim Abbott