add edit modal & fix some features

src/directives/btn-edit-snippet.js

@@ -0,0 +1,18 @@
+angular.module('codexen.directives')
+  .directive('btnEditSnippet', function (editSnippetModal, $rootScope) {
+    return {
+      scope:{
+        snippet: '=btnEditSnippet'
+      },
+      link: function (scope, el) {
+        el.on('click', function () {
+          editSnippetModal.open(scope.snippet)
+            .result.then(function (snippet) {
+              $rootScope.$broadcast('snippetUpdated', snippet)
+            }, function () {
+              console.log('edit snippet modal dismissed')
+            })
+        })
+      }
+    }
+  })