Daily Log 20170313
- Distance slider widget not responding to undo/redo for some reason

- Added slider widget quantization

- Slider widget now reports whether its value is being diddled by the mouse

- New "multiple values selected" display for a slider widget

- New "bi-directional" slider widget to show disposition behind or in front

- Need editable text field for disposition distance

- Add small hint "in front of" or "behind" depending if -ve or +ve

+ When in "Circle" disposition, need to replace slider with unidirectional one

+ Need to be able to right-align text in textfields

+ When you can't edit disposition distance no point in showing the slider

+ Need "multiple values selected" display for a text widget

+ Selection should identify by entity ID not reference - undo/redo should also refer to IDs not references