First step at reorganizing

src/ifcgeom/abstract_mapping.h

@@ -0,0 +1,15 @@
+#include "../ifcparse/IfcBaseClass.h"
+#include "../ifcgeom/taxonomy.h"
+
+namespace ifcopenshell {
+
+namespace geometry {
+    
+    class abstract_mapping {
+	public:
+		virtual ifcopenshell::geometry::taxonomy::item* map(const IfcUtil::IfcBaseClass*) = 0;
+    };
+    
+}
+
+}