move scatter PTS_LINESONLY in constant into separate file:

- use it in attributes and default step

Author: etpinard

src/traces/scatter/attributes.js

@@ -10,7 +10,8 @@
 
 var Drawing = require('../../components/drawing');
 
-var PTS_LINESONLY = 20;  // TODO put in constants/
+var constants = require('./constants');
+
 
 module.exports = {
     x: {
@@ -84,7 +85,7 @@ module.exports = {
             'If the provided `mode` includes *text* then the `text` elements',
             'appear at the coordinates. Otherwise, the `text` elements',
             'appear on hover.',
-            'If there are less than ' + PTS_LINESONLY + ' points,',
+            'If there are less than ' + constants.PTS_LINESONLY + ' points,',
             'then the default is *lines+markers*. Otherwise, *lines*.'
         ].join(' ')
     },

src/traces/scatter/constants.js

@@ -0,0 +1,14 @@
+/**
+* Copyright 2012-2016, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+
+'use strict';
+
+module.exports = {
+    PTS_LINESONLY: 20
+};

src/traces/scatter/index.js

@@ -47,10 +47,6 @@ Scatter.supplyDefaults = require('./defaults');
     ].join(' ')
 };
 
-// traces with < this many points are by default shown
-// with points and lines, > just get lines
-scatter.PTS_LINESONLY = 20;
-
 scatter.attributes = require('./attributes');
 
 scatter.cleanData = function(fullData) {