updated to work with php < 5.3.0 conditionally includes 5.3.0 code now, buffered any output during ajax calls, updated version numbers to 1.2.4

git-svn-id: https://plugins.svn.wordpress.org/work-the-flow-file-upload/trunk@907235 b8457f37-d9ea-0310-8a92-e5e31aec5664