Hello, I have noticed a small flickr issue on layers which have an opacity lower than 1.

If a layer has an opacity of 0.5 and you zoom in, it seems like the tiles are first loaded with opacity=1 and then are updated to opacity=0.5. This causes a weird flickr. This issue does not occur in leaflet 0.7.

Fiddle with leaflet 1.0-dev (zoom in and notice the flickr when the tiles are refreshing): http://jsfiddle.net/qf9huvk0/1/
Fiddle with leaflet 0.7.3 (no issues): http://jsfiddle.net/p6k4ejuq/3/

Is there any way I can solve this issue? Many thanks!