v0.3.3

Add WP Pilot, with Polsat, TV 4, Telewizja WP and more

WP Pilot streams some thirty channels free to an account. telesfor
now offers them from a tuner of their own at /wppilot, numbered
from 6001: the channels WP lists as free for the account, without
its radio stations, which have no picture, and without the four
that TVP's own tuner has. A channel's number is WP's number for it,
so it keeps it when others come and go.

The sign-in is the one WP Pilot's apps for TV sets use: telesfor
asks WP for a code and shows it with the page to enter it on, the
user signs in there, and telesfor, which has been asking meanwhile,
is handed the session, in the two cookies WP's own site keeps it
in. They go to WP's API alone, and are taken up as its answers
reissue them. A call that WP refuses with cookies another answer
has reissued meanwhile is made again; one it refuses with the
session as it is puts the sign-in to expired on the settings page.
WP plays a free account nothing until it has accepted WP's
consents, which the settings page says for as long as that lasts.
The guide looks after the account too: its consents, and the
channels it gets.

To WP a stream is a session of the account, of which it allows
three at once, which it wants told every twenty seconds that it is
watched, and which holds its place for minutes unless it is closed.
A channel has one session for all who watch it, opened for the
first and closed after the last: WP stops every stream of a channel
once the newest of the channel's sessions is closed, so with a
session each, a viewer who came later and left sooner would take
the channel from the rest. An open that WP refuses for the
account's limit while telesfor is closing a session is asked again
once that is done, as a change of channel needs. The tuner tells
Plex of three tuners, for which a device can now say how many it
has.

WP plays a free account's channels in a browser only, and its
stream servers answer a stream's playlists only to who opened the
stream, so every request names the same browser. What WP refuses is
told apart: a sign-in, the consents, an address outside Poland, an
address it takes for a VPN's, the limit of streams. WP's list does
not say which channels are DRM-protected, and WP names licence
servers for some that it streams in the clear, so the playlists
tell: a channel that is protected, or has no HLS stream, leaves the
lineup when it is first tuned, until the account signs out.

The guide is WP's own, which reaches about half a day. The rest of
the two days has the channel's name on every hour, and so has a
channel WP has no guide of.

- internal/provider/wppilot: the provider, its sign-in, its guide,
  their tests and a live test.
- internal/tuner: a device's number of tuners.
- cmd/telesfor/main.go: WP Pilot's tuner and -wppilot-proxy.
- README.md, docs/usage.md, docs/development.md,
  packaging/linux/telesfor.env: WP Pilot, its sign-in, its
  channels, its guide and its proxy.