Add informative messages to settings page

git-svn-id: https://plugins.svn.wordpress.org/instamojo/trunk@884544 b8457f37-d9ea-0310-8a92-e5e31aec5664
Remove old assets and use same logic as im-embed

git-svn-id: https://plugins.svn.wordpress.org/instamojo/trunk@884545 b8457f37-d9ea-0310-8a92-e5e31aec5664