removing version 2.3.1 from trunk

git-svn-id: https://plugins.svn.wordpress.org/file-away/trunk@981979 b8457f37-d9ea-0310-8a92-e5e31aec5664
adding 2.4 to trunk

git-svn-id: https://plugins.svn.wordpress.org/file-away/trunk@981984 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated stable tag

git-svn-id: https://plugins.svn.wordpress.org/file-away/trunk@981986 b8457f37-d9ea-0310-8a92-e5e31aec5664