Add 'Other' option for slave device contact type

This option alows for displaying XRef without contact drawing.
This is useful for spliting one physical part into multiple
logical elements when the slave element is not a switch.

sources/properties/elementdata.cpp

@@ -425,6 +425,8 @@ QString ElementData::slaveStateToString(ElementData::SlaveState type)
 			return QStringLiteral("NC");
 		case SW:
 			return QStringLiteral("SW");
+		case Other:
+			return QStringLiteral("Other");
 	}
 }
 
@@ -436,7 +438,9 @@ ElementData::SlaveState ElementData::slaveStateFromString(const QString &string)
 		return ElementData::NC;
 	} else if (string == QLatin1String("SW")) {
 		return ElementData::SW;
-	}
+	} else if (string == QLatin1String("Other")){
+		return ElementData::Other;
+    }
 
 	qDebug() << "ElementData::slaveStateFromString : string : "
 			 << string