Additional fix for from_name issue reported on Support Forum.

git-svn-id: https://plugins.svn.wordpress.org/email-users/trunk@946229 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added ability to edit notification email body and subject.

git-svn-id: https://plugins.svn.wordpress.org/email-users/trunk@946231 b8457f37-d9ea-0310-8a92-e5e31aec5664
Prep for 4.6.10 release.

git-svn-id: https://plugins.svn.wordpress.org/email-users/trunk@946233 b8457f37-d9ea-0310-8a92-e5e31aec5664