* pictures are removed from backup as well when deleted
* restore backup warning/error fixed
* fixed useless/bad AJAX requests that occured sometimes
* added user agent to API Key validation for debugging purposes
* Bulk Processing was freezing for some users, fixed this + added Cancel button



git-svn-id: https://plugins.svn.wordpress.org/shortpixel-image-optimiser/trunk@1040172 b8457f37-d9ea-0310-8a92-e5e31aec5664