Doc tweaks [ci skip]

src/ifcconvert/ColladaSerializer.cpp

@@ -338,6 +338,7 @@ void ColladaSerializer::ColladaExporter::endDocument() {
 	geometries.close();
 	for (std::vector<DeferredObject>::const_iterator it = deferreds.begin(); it != deferreds.end(); ++it) {
 		const std::string object_name = it->unique_id;
+        /// @todo redundant information using ID as both ID and Name, maybe omit Name or allow specifying what would be used as the name
 		scene.add(object_name, object_name, it->representation_id, it->material_references, it->matrix);
 	}
 	scene.write();

src/ifcconvert/IfcConvert.cpp

@@ -115,6 +115,7 @@ bool rename_file(const std::string& old_filename, const std::string& new_filenam
 static std::stringstream log_stream;
 void write_log();
 
+/// @todo make the filters non-global
 IfcGeom::entity_filter entity_filter; // Entity filter is used always by default.
 IfcGeom::layer_filter layer_filter;
 const std::string NAME_ARG = "Name", GUID_ARG = "GlobalId", DESC_ARG = "Description", TAG_ARG = "Tag";