Update plugin version to 1.1.

* Fix: Eliminate isset errors on product editing pages
* Add: Allow to create a product that is free for non-members after a certain date

git-svn-id: https://plugins.svn.wordpress.org/membership-product-restrictions-add-on-for-ithemes-exchange/trunk@916233 b8457f37-d9ea-0310-8a92-e5e31aec5664