Rendering update continuously

[AnthonyGlt]

When moving or zooming using the mouse, the mainloop will update the scene then when everything is loaded, the scene wont be updated anymore (expected because no new changes).

But if we call :

view.controls.lookAtCoordinate({
                coord: new itowns.Coordinates('EPSG:4326', 6.09,49.55,0),
                range: 3000,
                time: 1500,})

or

view.controls.setRange(3000)

then the scene get constantly updated (to verify). The function
#step(view, timestamp)
of mainloop.js is constantly called.

It should behave the same as the mouse movement, getting called only when necessary