User should be able to select a directory full of files without timing out

Right now the data loader is limited to loading 700 files at once, since loading too many (~900-1000?) causes the tool to timeout. I think this is a problem with the file tool itself because it tries to send all the files in one POST request. The current tool is gwtupload. We tried moxieapps gwt-uploader, which successfully uploaded all the files (one by one), but there was a problem getting the automated tests to work with it.