Merge pull request #155 from tylerlong/master

IE, local html, cssRules access is denied

src/utils.js

@@ -66,12 +66,14 @@ module.exports.cloneCssStyles = function(svg, classes){
             catch(err) {
                 if(typeof console !== 'undefined'){
                     if(console.warn !== 'undefined'){
+                        if(rule !== 'undefined'){
                             console.warn('Invalid CSS selector "' + rule.selectorText + '"', err);
                         }
                     }
                 }
             }
         } 
+    }
 
     var defaultStyles = "";
     var embeddedStyles = "";