DEICH-6408 - Fixed JS hangup on error from server while saving
DEICH-0000 - Added option to log out callback
Gives the application the possibility to display a correct message to the user about the invalid session and the need to log in again with tha application`s look and feel.
DEICH-6408 - Fixed JS hangup on error from server while saving
Also added more user-friendly alert message to the user.
General handling of HTTP status errors (401/403/500 so far).
Removed deepClone, and added a more capable seepCopy to lib/util.js.
Removed fetch polyfill try-catch in util.js. Polyfill is not used any longer.