Add a background highlight to vote count button if currently
logged in user votes on that option.
Tweaked by tabbott to use better variable names and Rishi for better
styling.
We had initially designed the poll widget like a blog
post with comments beneath it but it makes more sense
to think of it as just a simple poll with options.
NOTE: If you revert this commit, you want to revert
the immediately prior commit as well. The history
is that Ishan made some improvements to the widget,
but there were some minor bugs. I decided not
to squash the commits together so that the git
history is clear who did what. (In particular, I
want questions about the JS code to come to me if
somebody does `git blame`.)
Anyway...
This is a fairly significant rewrite of the polling
widget, where I clean up the overall structure of
the code (including things from before the prior
fix) and try to polish the prior commit a bit as
well.
There are a few new features:
* We tell "other" users to wait for the poll
to start (if there's no question yet).
* We tip the author to say "/poll foo" (as
needed).
* We add edit controls for the question.
* We don't allow new choices until there's
a question.
The user can also edit the question after adding it.
The question in the poll can only be added/edited
by the user who started the poll.
The input bar will be disabled for the other users
if the question is not yet added. If the question is
added, the input bar will not be visible to the other
users.
These styles aren't great, but they're hopefully
better than none at all and inspire a follow up
commit from somebody else (so it starts to look
like a "real" feature instead of feeling completely
proof-of-concept).
A "zform" knows how to render data that follows our
schema for widget messages with form elements like
buttons and choices.
This code won't be triggered until a subsequent
server-side commit takes widget_content from
API callers such as the trivial chat bot and
creates submessages for us.