AniBeam for Android 0.9.0

Endpoint repos (#143, #150): add a repo by its address, check its key fingerprint, then install the endpoints it offers. Erai asks for your RSS token and keeps it on the phone. Add an endpoint by hand for a site no repo carries, a Jackett feed such as 1337x among them; a key in the address moves to the phone's secret store. The first run gains an Endpoints step.