Fix a number of issues with talkie playback.

Summary:
This fixes a number of issues with taklie playback. Specifically:

- Scrubbing flashed hotnumber changes aggressively.
- Hitting play after seek:
  - The code reset back to its original state
  - The canvas drawing would get erased
- During seek:
  - Drawing would constantly be overwritten (line gets thicker)

Remove some test code.

Test Plan: I've added in a new audio demo that we can use to manually test playback. Attempt to play through the talkie and manually scrub around, making sure everything is working as expected.

Reviewers: brian, pamela

Reviewed By: pamela

Subscribers: alexrodrigues, #cs

Differential Revision: http://phabricator.khanacademy.org/D13672
Detect and send page info event which sends html title

Test Plan:
- Sets an event which is fired to the parent window when new
page info is obtained. Currently only title is supported.

Reviewers: pamela, john

Subscribers: #cs

Maniphest Tasks: T3238

Differential Revision: http://phabricator.khanacademy.org/D13600
Bring in multirecorder fix that Alex wrote. Update bower state.
Merge branch 'master' of github.com:Khan/live-editor
Remove extraneous argument to mouse playback. Fixes Mouse Interaction talkthrough.

Summary: During the recent refactor the name argument was removed to the mouse handlers, causing the `x` argument to become `y` and `y` to become `undefined`. This fixes that.

Test Plan: The Mouse Interaction talkthrough should now work!

Reviewers: brian, pamela

Reviewed By: pamela

Subscribers: #cs

Differential Revision: http://phabricator.khanacademy.org/D13787
Refactoring and testing tooltip-engine.js (previously called hotnumber.js)

Test Plan:
- See that all four kinds of widgets pop up in the editor
- Check that all of the tests pass
- Check that the three editable widgets correctly alter the text
- Check that autoSuggest has priority over numberScrubber normally and vice-versa on click
- Check that colorPicker has priority over numberScrubber
- Watch "Nested for loops" to verify playback.

Reviewers: pamela, john

Reviewed By: john

Subscribers: brian, #cs

Maniphest Tasks: T3193

Differential Revision: http://phabricator.khanacademy.org/D13126
Final clean up

Test Plan:
<see below>