Attaches editor to the AFRAME global variable

[fernandojsg]

It will break all the references to editor in the rest of the code.

[dmarcos]

I think your code should not use the externally exposed API

[dmarcos]

changing the public facing API should not affect the code internally

[dmarcos]

I made the editor expose a singleton instead of the constructor. The other modules import it instead of relying in the editor variable of the window object. This way we decouple the internal from the publicly exposed API.

[fernandojsg]

superb! thank you :)