Provide app context to JS client code

[Dylan McCall]

We need to tell the JavaScript code that it is inside the Kolibri app, that there is no sharing capability, etc. I believe we can do this by creating some global objects, or something along those lines, although I'm unclear about how this all works…

[Devon Rueckner]

cc @kollivier @rtibbles

[Richard Tibbles]

This is done.