popup login seamless session continuation

[tablatronix]

do an onbeforeunload intercept, ajax check logged in status.
If not logged in allow popup authentication over ajax, perform refresh or submit etc.

Do the same for nonce or csrf failure

[tablatronix]

for simple solution, provide a textfield with data to at least be able to copy and save for browsers that do not restore, also possibly implement ckeditor autosave using js local storage...