Implemented offset on solids. There were at least two possibilities to offset solids one using BRepOffset_MakeOffset and one using BRepPrimAPI_MakeThickSolid. The implemented tool is using the first API and generates an offset duplicate after the selected solid. On next iterations will schedule also some offsetting that creates shells and other shelling tools (that wold be using the second API).
The offset shape is parametrically influenced by the modifications on source objects. Implemented also descriptor for offset so that the offset can be changed in the property grid.