Implement continuous tape labels and path-based label shapes.

- Added "roll" as a special paper id
- Added roll_width attribute to draw tape in previews
- Updated Brother QL-500/* label templates
- Preserve print dialog settings between print jobs.
- Added path based labels for arbitrary shaped labels.
- Fleshed out implementation of continuous labels.

model/Distance.cpp

@@ -208,3 +208,13 @@ namespace glabels
 
 	}
 }
+
+
+QDebug operator<<( QDebug dbg, const glabels::model::Distance& distance )
+{
+	QDebugStateSaver saver(dbg);
+
+	dbg.nospace() << distance.pt() << "pt";
+
+	return dbg;
+}