editor: add focusNode() method

This adds Google Maps like animation on focus of a given node.

https://www.youtube.com/watch?v=4rrQGZsGCK0

Not so happy with the react.animate dependency.
Given the fixes I had to make, I wonder how this ever worked for anybody : 

https://github.com/pleasetrythisathome/react.animate/commit/7d77b0de2bf680882ccb867c839740a3785070da
https://github.com/pleasetrythisathome/react.animate/commit/340b1f90243d8b7c8a4db8c9c8b90c705b23c818
https://github.com/pleasetrythisathome/react.animate/commit/8d1b97d4b0d578c7cd65bc072f5647a119a57fcf

Oh well... YOLO they say...