Add basic support for @mixin and url to where its defined

context-free-parser.js

@@ -60,7 +60,7 @@
               };
               entities.push(current);
               break;
-            
+
             // an entity may have these describable sub-features
             case 'attribute':
             case 'property':
@@ -94,7 +94,17 @@
               }
 
               break;
-
+
+            case 'extends':
+            case 'mixins':
+              var parts = content.split(' ');
+              var subObj = {
+                name: parts[0],
+                url: parts[1] || null
+              };
+              makePragma(current, pragma, subObj);
+              break;
+
             // everything else
             default:
               current[pragma] = content;