Provide possibility to perform Boolean operations on open solids.
Implementation of the new method *BOPAlgo_Builder::BuildBOP* performing the construction of the result shape for the given type of Boolean operation.
This approach does not rely on the splits of solid to be correct and looks for the faces with necessary state relatively opposite solids to build the result solid.
The call to this method is performed from BOP algorithm in case there were open solids in the arguments.
Implementation of the draw command *buildbop* performing a call to the method above.
