Allow user to choose which post types to enable backdrop slideshow feature on

git-svn-id: https://plugins.svn.wordpress.org/jellyfish-backdrop/trunk@1050715 b8457f37-d9ea-0310-8a92-e5e31aec5664
Allow user to choose which post types to enable backdrop slideshow feature on

git-svn-id: https://plugins.svn.wordpress.org/jellyfish-backdrop/trunk@1050716 b8457f37-d9ea-0310-8a92-e5e31aec5664