wip of audience feedback
Add audience interaction. Bumps version to 0.9.6

This uses the websocket messaging from the last update to pass other
messages around. This allows the users to:

* Tell the presenter to slow down or speed up.
* Ask the presenter a question
* Provide feedback to the content authors about specific slides.

To access the interface, the user should simply move their mouse near
the left hand side of the screen. The buttons will be disabled and a
disconnected icon will appear in the lower right corner in case of
connectivity problems.

Slide feedback is saved in the feedback.json file, indexed by slide
name. We should determine policy for getting the file back to us.
Docs updates for the new hotness
Added note about disconnected icons
Enable feedback with setting in showoff.json

This defaults to not showing the new feedback interface.
We will enable it for trainings after it's been tested more.
Doc update & fix for out of scope variable

Updates the docs to make a note that the feedback bit is optional
I was accessing a variable out of current scope that happened to set to
contents similar to what I was expecting most of the time. Until it
wasn't, then things blew up. So I fixed that.
Some final cleanups
Reconnects to server and provides user feedback.

This commit does two things:

1. When the connection to the server is disrupted for whatever reason,
the client running in the browser will attempt to reconnect every 5
seconds. This includes when the server itself is stopped and restarted.
2. Any time an audience member sends feedback, an indicator showing
that something is happening is displayed.
Added an anonymity disclaimer
Adding changelog
Merge pull request #99 from binford2k/features/audience_feedback

Add audience interaction. Bumps version to 0.9.6