[patch] HTTP_WebDAV_Server

I've been investigating using PEAR's WebDAV server in a production environment, and I've found a few issues. This patch revolves the first which is poor memory performance due to the use of fpassthru(). I've added a member function called _send_stream(resource handle) which buffers the output to the webdav client and replaces the fpassthru() calls. I've tested it and found memory usage to be improved. The goal of my efforts is to improve webdav performance for concurrent requests for large files. Thanks, Alex