added new functional version of the plugin; fixed major bug with signups

git-svn-id: https://plugins.svn.wordpress.org/landing-pages-builder/trunk@842103 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated changelog and upgrade notice

git-svn-id: https://plugins.svn.wordpress.org/landing-pages-builder/trunk@842104 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated changelog and upgrade notice

git-svn-id: https://plugins.svn.wordpress.org/landing-pages-builder/trunk@842105 b8457f37-d9ea-0310-8a92-e5e31aec5664