Only load assets into memory while sending them to the Companion.

This should reduce the javascript memory needed for projects with a
lot of assets.

Change-Id: I55eda14204f4273a5d6c93cd221c98fd39ef054c
Alter the way Companion Updates Happen – Use Push

The AI Client code (in the browser) now downloads the new
Companion (from the service) and “pushes” it to the Companion using a
mechanism similar to the mechanism used to send assets to the
Companion. This eliminates difficulties encountered when a proxy
exists between the Internet and the AI user’s location.

Change-Id: I5d91de137d2ed57199949b0761fdf13fa24fa8fe