Fix __filename in node

c3.js

@@ -3,12 +3,12 @@
 
     /*global define, module, exports, require */
 
-    var __filename; // used in Node.js to get css file using path
+    var __filename__; // used in Node.js to get css file using path
     var c3_chart_fn, c3_chart_internal_fn;
     var c3 = { version: "0.4.9" };
 
     var c3init = function(module){
-        __filename = module.uri;
+        __filename__ = module.uri;
         return c3;
     }
 
@@ -104,7 +104,7 @@
         var css, rule, sheet, value;
         if(isNode()){
             if(!nodeCss){
-                var style = require('fs').readFileSync(__filename.replace('c3.js', 'c3.css'), 'utf-8');
+                var style = require('fs').readFileSync(__filename__.replace('c3.js', 'c3.css'), 'utf-8');
                 nodeCss = [require('css').parse($$.ed3Config.style), require('css').parse(style)];
             }
 
@@ -8578,6 +8578,7 @@
     if (typeof define === 'function' && define.amd) {
         define("c3", ["module", "d3", "async-buffer"], c3init);
     } else if ('undefined' !== typeof exports && 'undefined' !== typeof module) {
+        __filename__ = __filename;
         module.exports = c3;
     } else {
         window.c3 = c3;

src/core.js

-var __filename; // used in Node.js to get css file using path
+var __filename__; // used in Node.js to get css file using path
 var c3_chart_fn, c3_chart_internal_fn;
 var c3 = { version: "0.4.9" };
 
 var c3init = function(module){
-    __filename = module.uri;
+    __filename__ = module.uri;
     return c3;
 }
 
@@ -99,7 +99,7 @@ function getStyleValue($$, selector, property) {
     var css, rule, sheet, value;
     if(isNode()){
         if(!nodeCss){
-            var style = require('fs').readFileSync(__filename.replace('c3.js', 'c3.css'), 'utf-8');
+            var style = require('fs').readFileSync(__filename__.replace('c3.js', 'c3.css'), 'utf-8');
             nodeCss = [require('css').parse($$.ed3Config.style), require('css').parse(style)];
         }
 

src/tail.js

     if (typeof define === 'function' && define.amd) {
         define("c3", ["module", "d3", "async-buffer"], c3init);
     } else if ('undefined' !== typeof exports && 'undefined' !== typeof module) {
+        __filename__ = __filename;
         module.exports = c3;
     } else {
         window.c3 = c3;