Work on the card activities and comments

This commit also introduces a new CSSEvents object that is used to
abstract vendor specifics events related to CSS transitions and
animations.

Fixes #183.
Fixes #179.

client/components/activities/comments.js

@@ -0,0 +1,49 @@
+var commentFormIsOpen = new ReactiveVar(false);
+
+Template.commentForm.helpers({
+  commentFormIsOpen: function() {
+    return commentFormIsOpen.get();
+  }
+});
+
+Template.commentForm.events({
+  'click .js-new-comment:not(.focus)': function() {
+    commentFormIsOpen.set(true);
+  },
+  'submit .js-new-comment-form': function(evt, tpl) {
+    var input = tpl.$('.js-new-comment-input');
+    if ($.trim(input.val())) {
+      CardComments.insert({
+        boardId: this.boardId,
+        cardId: this._id,
+        text: input.val()
+      });
+      input.val('');
+      input.blur();
+      commentFormIsOpen.set(false);
+      Tracker.flush();
+      autosize.update(input);
+    }
+    evt.preventDefault();
+  },
+  // Pressing Ctrl+Enter should submit the form
+  'keydown form textarea': function(evt, tpl) {
+    if (evt.keyCode === 13 && (evt.metaKey || evt.ctrlKey)) {
+      tpl.find('button[type=submit]').click();
+    }
+  }
+});
+
+Template.commentForm.onDestroyed(function() {
+  commentFormIsOpen.set(false);
+});
+
+EscapeActions.register('inlinedForm',
+  function() {
+    commentFormIsOpen.set(false);
+    $('.js-new-comment-input').blur();
+  },
+  function() { return commentFormIsOpen.get(); }, {
+    noClickEscapeOn: '.js-new-comment'
+  }
+);