By enabling the setting in IFC preferences, the IFC
importer can now detect if an input shape is a normal
extrusion, and create the object as a Part::Extrusion.
* Added utility to make non-parametric Arch component
* Ability for all Arch components to be a clone of another Arch component of same type
* Modified the Draft Clone tool to produce Arch Clones if applicable
* Fixed Arch Roofs so they can be based on a solid shape like other Arch objects
* Ability to change the Root element to be imported in IFC preferences
* Ability to import IFC files also as compounds, Part shapes or non-parametric Arch objects
* Added an "only" parameter to importIFC.open() to import only a certain object ID.
* Ability to read colors (IfcSurfaceStyle) from IFC objects
* Uses DXF algos of the Drawing module instead of the Draft dxf library
* Uses a DXF template with the same name as the SVG template, if existing
* Only Draft, Arch, Part and Annotation views are currently supported
* Drawing module's projectToDXF() now returns only a fragment instead of a full DXF file
* makeCompoundFromSelected: creates a compound object from selected subobjects
* cleanArchSplitter: cleans the splitters on imported Arch objects
* rebuildArchShape: tries to rebuild a solid from the faces of an invalid shape
* Removed roundings in exported objects
* Added toggleIfcBrepFlag command to force export as BREP
* Prepared Arch objects for Materials and custom IFC attributes
* Supported latest developement version of IfcOpenShell
* Cleanup of IFC exporter
* Export of Arch Sites as IfcSite
* Export of Groups as IfcGroup
* Removed redundant code in Arch objects
* Supports wandererfan's Units code in Draft module
* Cleanup of the IFC exporter
* Better support of extruded profiles in IFC export
