Tweak plugin to work for our needs

Hey,

I have modified the jquery sdk plugin to cater for our needs. Can I explain to you my needs and see if I am doing the right thing?

- Upload needs to start as soon as a file has been picked
- Form must not be submitted until user has clicked Submit (Can't be submitted while uploads are in progress)

I know my needs sound pretty basic but I could not get the plugin to work in its current condition. Was I doing something wrong?

See below for our current config.
```
      wait: false
      modal: false
      autoSubmit: false
      processZeroFiles: true
      triggerUploadOnFileSelection: true
      params: @params
      signature: @signature
```

Cheers,
Daniel