1.9.17 stable

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@949511 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme tweak

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@949515 b8457f37-d9ea-0310-8a92-e5e31aec5664