revert previous commit - re-enable textarea overrides
add method to pass textarea overrides to editor. Currently only functional with CKEditor.

@espaan @nmpetkov

This should work. I am having trouble testing everything atm because my system is botched up. I was able to add an override like `uiColor:#0099FF` for one textarea and it works. changing the toolbar works, but there are weirdnesses there that have to do with our default config I think (see the editortemplate file).