v1.5 released. 
- Allowed to use 'custom' parameter in url to track custom variables ( http://your-wordpress-website/landing-page?custom=custom-value-to-pass )
- Allowed to force certain variation to display ( http://your-wordpress-website/landing-page?variant=B )


git-svn-id: https://plugins.svn.wordpress.org/instapage/trunk@844464 b8457f37-d9ea-0310-8a92-e5e31aec5664