[TYPO3-core] FYI #15950: use t3editor in file_edit to edit files in fileadmin

[Steffen Kamper]

Hi Tobi,

great to find this here!

Two questions regarding codemirror
1) is this the latest version?
2) Shouldn't we move codemirror to typo3/contrib and maintain there, so 
we can use it in ExtJS as well? It's very dirty to include something 
from extension, especially extension isn't installed.

vg Steffen