Minor updates, compatibility with Wordpress v4

git-svn-id: https://plugins.svn.wordpress.org/pmid-citations-with-read/trunk@1042527 b8457f37-d9ea-0310-8a92-e5e31aec5664
Minor updates, compatibility with Wordpress v4

git-svn-id: https://plugins.svn.wordpress.org/pmid-citations-with-read/trunk@1042528 b8457f37-d9ea-0310-8a92-e5e31aec5664