Consider deprecating `webtorrent-hyrbid` and moving `wrtc` into `webtorrent`

[feross]

webtorrent-hybrid and the global.WEBTORRENT_ANNOUNCE is kind of a hack.

The whole reason I created webtorrent-hybrid was that installing the WebRTC in Node.js package (wrtc) used to cause lots of install warnings/errors for most users at one point in time. If the situation has improved since then, we can just include wrtc directly in the webtorrent package and deprecate webtorrent-hybrid.

We can try including wrtc in one version of webtorrent to see how many install errors it causes and if all looks good, then we can eventually deprecate webtorrent-hybrid.

Originally posted by @feross in #1604 (comment)