Fix bug preventing animated "Map#rotateTo" operations inside "moveend" event listener

[lcapel]

Hi, I'm using the latest version of Mapbox GL JS (0.20.1) and I have this issue where when I try to call rotateTo() after a moveend event fires nothing happens. If I try to call flyTo() instead, it works. I'm not sure if I'm doing anything silly, here are two simple examples demonstrating the issue.

http://jsbin.com/demecovehi/1/edit?html,console,output - Fly after move end

http://jsbin.com/komaloceci/1/edit?html,console,output - Rotate after move end

[lucaswoj]

This bug can be avoided by setting duration to 0 or placing the call to rotateTo within a setTimeout(..., 0) block. I suspect we are getting tripped up by the inability to have multiple overlapping camera animations.

There is likely an easy fix to this issue by ending the camera animation before emitting the "moveend" event.

related to #2801

[lcapel]

The workaround will get me going for now, thanks for the tip! Using requestAnimationFrame(() => { ... } ) will also do the same thing 👍