fix wrapping br to paragraphs

Author: linkesch

src/js/core.js

@@ -305,7 +305,7 @@
         $text = this.$el
             .contents()
             .filter(function () {
-                return this.nodeName === '#text' && $.trim($(this).text()) !== '';
+                return (this.nodeName === '#text' && $.trim($(this).text()) !== '') || this.nodeName.toLowerCase() === 'br';
             });
 
         $text.each(function () {