performance improvements

+ use const-reference as argument to avoid tmp. copy
+ use prefix incremation operator instead of postfix increment operator

src/Mod/TechDraw/App/GeometryObject.cpp

@@ -76,7 +76,7 @@ struct EdgePoints {
     TopoDS_Edge edge;
 };
 
-GeometryObject::GeometryObject(std::string parent) :
+GeometryObject::GeometryObject(const string& parent) :
     Scale(1.f),
     m_parentName(parent),
     m_isoCount(0)