Check if selector matches parents of test element

Previously a menu for a keybinding with a .workspace selector would not
display the shortcut because the selector wasn't matching the test editor
element directly.

Now the parent elements of the test editor are checked as well.

Closes #2089

src/menu-manager.coffee

@@ -69,7 +69,12 @@ class MenuManager
       @testEditor.classList.add('editor')
       testWorkspace.appendChild(@testEditor)
 
-    @testEditor.webkitMatchesSelector(selector)
+    element = @testEditor
+    while element
+      return true if element.webkitMatchesSelector(selector)
+      element = element.parentElement
+
+    false
 
   # Public: Refreshes the currently visible menu.
   update: ->