Improve support of video and sequence textures.

Now, if you add video (image sequence) as texture node (Cycles, Eevee) it will be updated in 3d-view in this case only:

1. auto refresh clicked
2. Image node selected - if it isn't it won't be updated even in OpenGL render button. Even if auto refresh clicked..
3. manually change frame - play via Alt+A not supported! Even if auto refresh clicked..

Tested on Eevee 2.8, Cycles 2.79