Specification and save file format for widgets and nodes. Widgets have XYZ bounds and top/bottom attachments (for floor or ceiling-based widgets). Widget bounds are categorized as tiny, small, medium, large, or huge.

Size | X | Y | Z
tiny 2 2 2
small 3 3 3
medium 4 4 4
large 6 6 6
huge 8 8 8

Widgets may also specify a list of acceptable themes in which they can be placed.

Closing this issue as the base widget classes are complete. Implementation of editor and generator support is ongoing.