Viewer doesn't work in production mode (with optimizations & transitions active)

[marcusforsberg]

When building with optimization: true, the Viewer starts acting weird in modal mode. Opening an image will trigger the Viewer itself to open, but the image isn't visible. Sometimes the image pops up after a few seconds, but always randomly. Even weirder, hovering over any of the toolbar buttons will trigger the image to pop up immediately.

Disabling transitions on Viewer.js fixes this, so we've disabled them by default with a note in the readme.

We should find a way to fix this properly.