Updating readme.txt.

git-svn-id: https://plugins.svn.wordpress.org/easy-theme-and-plugin-upgrades/trunk@923246 b8457f37-d9ea-0310-8a92-e5e31aec5664
Releasing version 1.0.4.

git-svn-id: https://plugins.svn.wordpress.org/easy-theme-and-plugin-upgrades/trunk@923252 b8457f37-d9ea-0310-8a92-e5e31aec5664