[TYPO3-core] RFC #12164: Use flashmessages to display messages in fileadmin

[Rupert Germann]

Steffen Gebert schrieb:
> Would it be a big effort to show the show the message not in an extra 
> screen but return to the directory listing and show the warning on top?

no effort at all. Just set the "isSessionMessage" flag in the 
flashmessage and remove the output part.

see attached patch and screenshot

I'll change 12138 accordingly (tcemain) if we agree that this is the 
better way.

greet
rupert