add TlsAcceptor::with_acceptor method

[MarinPostma]

This PR add a AcceptorBuilder::with_connector method that takes a generic acceptor implementing Accept.
This is necessary when you need to work with any other acceptor than AddrIncomming.

[djc]

This mostly makes sense to me. I'd prefer to keep the bounds in the impl definition where possible (impl<C: AsyncRead + AsyncWrite + Unpin> TlsStream<c>).

Do you have a sense of whether this is semver-compatible? If not, can you add a semver-breaking version bump in a separate commit?

Out of curiosity, what do you (want to) use instead of AddrIncoming?

[MarinPostma]

@djc thanks, I will do as suggested

We're abstracting networking in our project to implement simulation with turmoil. So I have a custom acceptor that wraps a turmoil TcpStream

[MarinPostma]

as for semver, I'm not completely certain. It seems to me that yes, thanks to the default types, but I'm not an expert enough on semver.

[djc]

I think this documentation says it should be okay.

[MarinPostma]

@djc, I fixed fmt and fixed the trait bounds 👍

[djc]

LGTM, thanks!

[djc]

@cpu do you want to take a look?

[cpu]

Thanks, LGTM