Chunked File Uploads

Hi,

When we were uploading huge files we discovered that we were making poor Banjo run out of heap space.  That's because it was loading the huge files into memory before putting them to disk.  Many of them at the same time was problematic.

You can send files in 10MB chunks with the Content-Range HTTP header.  I needed to make JobsController be able to read the Content-Range headers.  The JobRecord receiveFile method has been deprecated and split into three parts: new, append and finish.  The JobFile is only created once the upload is finished.

This should make things a lot smoother when uploading a lot of large files.

Cheers,
Huw.