Updated code for latest Wordpress Version 4.0

git-svn-id: https://plugins.svn.wordpress.org/simple-math-calculator/trunk@1008964 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated code for latest Wordpress Version 4.0

git-svn-id: https://plugins.svn.wordpress.org/simple-math-calculator/trunk@1008965 b8457f37-d9ea-0310-8a92-e5e31aec5664