fewer confusing callbacks..

We would get two scanning loops both scanning for qr codes. This makes
sure only one loop is active at all times.

This reverts commit 3c5c82f9.

so they can be reused

This API isn't suported in any browser we support, it used to work in
old chrome.

Still raw the image and everything all the time to keep the experience smooth.
One more improvement would be to also skip the image data extraction, but that can
be done after the clipping work.

We no longer bundle keycloak-js with rollup so we can remove those
special cases.

This makes sure the library version works with the server version.

Ideally we'd also want to check the version so we can error out if a too
old keycloak server is on the other side, but I don't see any public API changes
that would allow us to know if the library is too old.

Fixes #32

See #32

In my case it was ":1", making ffmpeg fail to record the screen.

I couldn't find any breaking changes affecting us

Instead of throwing an error set activeCamera to its initial value.

It's a webpack plugin, so unlikely that it is used.