Cleaned code for compatibility with WP 4

git-svn-id: https://plugins.svn.wordpress.org/wp-extra-options/trunk@1021224 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fixed version in readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-extra-options/trunk@1021225 b8457f37-d9ea-0310-8a92-e5e31aec5664
Removed readme.md

git-svn-id: https://plugins.svn.wordpress.org/wp-extra-options/trunk@1021226 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme.txt updated

git-svn-id: https://plugins.svn.wordpress.org/wp-extra-options/trunk@1021227 b8457f37-d9ea-0310-8a92-e5e31aec5664