Unify org.http4s.websocket package, use ByteVector

[rossabaker]

The org.http4s.websocket package is awkwardly split across the http4s-websocket repo and http4s-core. No package should ever live in two artifacts.

The reason for the http4s-websocket repo was to share a model between blaze and http4s without adding any dependencies to the former. Since then, the blaze repo dropped websocket support entirely. If we unify it here, we can use a model with all our dependencies. This includes ByteVector, which is back on our classpath since fs2-core again depends on scodec-bits. That gives us an immutable model.

There are all kinds of shady numeric truncations and widenings going on here, and it's worth looking closely at the WebSocketFrame class.

Additionally, standardizes on the WebSocket capitalization in place of Websocket

[cquiroz]

As a concept i totally support this

[rossabaker]

We should also release a blaze milestone without the old dependency to ensure that we're no longer using it.

[jmcardon]

LGTM. I agree it was awkward.

[jmcardon]

whoops, double approval was accident.