downloader.py will download RFP LaTeX from a Remit site, compile it, and allow you to print it.

Configuration is with a settings.py file in the same directory. It should
define:
- `baseurl`: the base of your Remit install (eg, baseurl + 'admin/' should give
  the admin)
- `pathtpl`: path into which to write output files (LaTeX and PDFs); this
  should be a printf-style string with named parameters `label` and `ext`
- `django_username` (optional): username to log in with; the script uses
  "downloader" if you don't override it
- `password`: password to log in with
- `pdfviewer` (optional): PDF viewer to automatically launch after compiling
  the LaTeX (default: evince)