Adding API.get_patrol_token() and wiki list.

API.get_patrol_token() gets a patrol token from the API and assigns it
to the name self.patrol_token (which is None by default).

Also adding a namedtuple of wikis, so one doesn't have to type the
entire API url when instantiating the API class. Currently the
namedtuple only has enwiki and dawiki, because those are the only wikis
I care about.
Better way to obtain patrol token.

Now using the API call "action:tokens" for obtaining patrol tokens.
Bumping to 0.3.1.