TYPO3 Core

RTE .css is still messy and most .css is duplicated in ext:rte and ext:t3skin

Goal is to move the .css to .less and compile the final .css like it is done for other extensions.

The final .css should reside in ext:rte and the files from t3skin should vanish.

Be aware that the contentcss.css (a file that is local for a single editor and can change the editor text body area to align with an FE view) can be changed via config and should therefor not be included in the .less transition.