Check version 3.7.1

git-svn-id: https://plugins.svn.wordpress.org/wp-copysafe-pdf/trunk@794321 b8457f37-d9ea-0310-8a92-e5e31aec5664
Windows 8.1 support

git-svn-id: https://plugins.svn.wordpress.org/wp-copysafe-pdf/trunk@794323 b8457f37-d9ea-0310-8a92-e5e31aec5664