Fix quotes and other encoded characters in export

git-svn-id: https://plugins.svn.wordpress.org/visual-form-builder/trunk@814376 b8457f37-d9ea-0310-8a92-e5e31aec5664
Remove screen_icon which has been deprecated in WordPress 3.8

git-svn-id: https://plugins.svn.wordpress.org/visual-form-builder/trunk@814377 b8457f37-d9ea-0310-8a92-e5e31aec5664