Updating to version 2.8.1. See changelog for details.

git-svn-id: https://plugins.svn.wordpress.org/ninja-forms/trunk@990440 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fixing a small bug with redirect notifications.

git-svn-id: https://plugins.svn.wordpress.org/ninja-forms/trunk@990444 b8457f37-d9ea-0310-8a92-e5e31aec5664