Add empty holes to boxes
Further drag and drop progress

Widgets are position absolutely except when inside other widgets (e.g.
boxes).
Made progress with empty holes in boxes.
More drag and drop progress

drop_on now takes the element as well and this simplifies backside drop
code.
Began to include operator in number display -- not yet operational.
Improved sizes of widgets on backsides

Added min-width and min-height while on backside.
Further improvements to sizes
More work on widget sizes

Problems remain.