Fix jump marker when zoomin or zoomout

[emmanuelroecker]

Fix jump marker when zoom in or zoom out

[ewoken]

1. For the pause and resume during zoom in/out animation:
   It improves the animation but it is not good because the time of the animation is "lost" and the marker will not be in time at the next station (try with small duration)

2. For pausing when the document is hidden:
   This feature has to be decided by the user. Some of them may want that the (real-time) animation still continues.

[emmanuelroecker]

Ok, I understand.
Perhaps, they can be in options.
As it's used in http://lyon.glicer.com for animations.

Best regards