Fix drawing stacked-100 problem

src/axis.js

@@ -376,7 +376,11 @@ c3_chart_internal_fn.tuneAxis = function(sync, callback){
 
     $$.pushCallback(callback);
 
-    if(!$$.config.stacked){
+    // if we don't need to tune
+    if($$.config.stacked){
+        $$.cachedRedraw();
+        return;
+    }
         
     var apply = function(){
 
@@ -409,7 +413,6 @@ c3_chart_internal_fn.tuneAxis = function(sync, callback){
         $$.buffer.onlastfinish("tune-axis", apply);
         $$.buffer.onlastfinish("cached-redraw", function(){});
     }
-    }
 
 };
 

src/callbacks.js

@@ -32,7 +32,7 @@ c3.chart.internal.fn.cachedRedraw = function(options, callback){
 
     $$.pushCallback(callback);
 
-    if($$.shouldCache){
+    if($$.config.shouldCache){
         if(!$$.buffer.has("tune-axis")){
             $$.buffer.onlastfinish("cached-redraw",
                 function(){

src/config.js

@@ -192,7 +192,9 @@ c3_chart_internal_fn.getDefaultConfig = function () {
         },
         tooltip_init_show: false,
         tooltip_init_x: 0,
-        tooltip_init_position: {top: '0px', left: '50px'}
+        tooltip_init_position: {top: '0px', left: '50px'},
+        // caching
+        shouldCache: true
     };
 
     Object.keys(this.additionalConfig).forEach(function (key) {