deselect annotation

static/js/annotation.js

@@ -6,9 +6,16 @@ oml.ui.annotation = function(annotation, $iframe) {
         .html(Ox.encodeHTMLEntities(annotation.text).replace(/\n/g, '<br/>'))
         .on({
             click: function(event) {
-                that.select()
+                var id
+                if (event.ctrlKey) {
+                    that.deselect()
+                    id = null
+                } else {
+                    that.select()
+                    id = annotation.id
+                }
                 $iframe.postMessage('selectAnnotation', {
-                    id: annotation.id
+                    id: id
                 })
             }
         });