Splitter POC, and uimodel JSON on LHS. L&F OK, but impl. still WIP..
Field UID not used anymore (with ng-form now), for the moment
addFieldsModelDerrivedState() - IMPORTANT for live editing
L&F of uimodel textarea
stuff for a 'handle' icon on the splitter vbar (later, untested)
field <label> is now contenteditable - nice