Add support for multiple snout images.

This will enable us to match against the average of several snout images. From playing with a prototype it gives better results.
Bump verison to 0.2.0
Add support for specifying multiple snout images.

The command line parser now can handle multiple values per option.

You can type either:
--snout_paths <path1> <path2>
or
--snout_path <path1> --snout_path <path2>

This way you can also add multiple snouts via the config file:
snout_path=<path1>
snout_path=<path2>

This will enable to add support for using the average of multiple snouts to calculate a better match compared to using just one.