Make sunburst and treemap sort optional

src/traces/sunburst/attributes.js

@@ -203,6 +203,7 @@ module.exports = {
             'this option won\'t have any effect and `insidetextfont` would be used.'
         ].join(' ')
     }),
+    sort: pieAttrs.sort,
 
     domain: domainAttrs({name: 'sunburst', trace: true, editType: 'calc'})
 };

src/traces/sunburst/calc.js

@@ -192,7 +192,9 @@ exports.calc = function(gd, trace) {
     if(failed) return;
 
     // TODO add way to sort by height also?
-    hierarchy.sort(function(a, b) { return b.value - a.value; });
+    if (trace.sort) {
+        hierarchy.sort(function(a, b) { return b.value - a.value; });
+    }
 
     var pullColor;
     var scaleColor;

src/traces/sunburst/defaults.js

@@ -73,6 +73,8 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
 
     coerce('insidetextorientation');
 
+    coerce('sort');
+
     handleDomainDefaults(traceOut, layout, coerce);
 
     // do not support transforms for now