Add capability checks to the page inclusion and save function

git-svn-id: https://plugins.svn.wordpress.org/string-locator/trunk@943067 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update deprecated capability for menu locations

git-svn-id: https://plugins.svn.wordpress.org/string-locator/trunk@943068 b8457f37-d9ea-0310-8a92-e5e31aec5664