Luminoso-api

* Upload script changes

- Add an option to specify the date format of the uploaded file.

* Client changes

- Use `ftfy.guess_bytes` instead of `chardet.detect`, which was frequently
detecting valid UTF-8 as ISO-8859-2.

* Client changes

- Removed support for non-token authentication.
- New `save_to_file` method allows saving API output directly to a file.
- Removed ftfy dependency, because ftfy is now run on documents after
they are uploaded.

* Client changes

- Upgrade dependency to python requests 1.2.1 or later, but not python
requests 3.
- Stop using the deprecated /preload/ endpoint.
- Support for token authentication.
- Remove obsolete `proxies` and `auto_login` parameters to connect().
- Python 3 compatibility.

* Server changes

- Support for token authentication.

* Client changes

- Don't send "width=n" to the /preload/ endpoint, because it doesn't
do anything.
- Send the reader configuration given on the command line to the
/recalculate/ endpoint.
- Get rid of root_url as a client parameter, because nobody used it
and it didn't actually work.

* Server changes

- API endpoints will now return an error when you give them unexpected
arguments. /preload/ accepts some arguments for backward compatibility.

* Update the documentation to match the changes in 0.4.1.