Allow the user to export / import his identification data

[mullerch]

Currently, the users are identified by a generated UUID stored in the browsers local storage. Therefore, the user has to use always the same browser to keep the same ID.

We could allow the user to export and import this data so that he can change the used browser, or use two different platforms (desktop / mobile).

An idea is to use a QR code generator to encode the data and show the code when the user submitted the data. The user can then scan the QR code from any other browser and the identity will be added locally to the browser.

[pksec]

It is an interesting feature. But be aware that it might be difficult for people with less knowledge to use this feature. Can we make it as optional feature - not the default or only available feature?