Fix repositioning widgets.
Fix repositioning widgets.

I noticed two defects in positioning widgets.  If you position a widget, a css property gets set and had no way to get unset.  Therefore, if you set the position via x, y or top, left, then tried to set it by bottom, right, the top, left css would still be present and prevent the desired position.  Further, 'px' was always added to the style, preventing clearing parameters via 'auto' or null (or using expressions like '20%').

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