Change retransmittable to Ack-eliciting

[ianswett]

Ack-eliciting is slightly shorter than retransmittable and seems as accurate as anything we have.

Fixes #1595

[marten-seemann]

We considered ack-eliciting before. I'm still not a big fan of it, but I can't say anything against it other than retransmittable reads a bit better.

[mikkelfj]

Yeah - retransmittable doesn’t mean it has to, only that it can be.

[ianswett]

I'm not set on this being what we go with, but I think it reads reasonably well and I'm really unhappy with retransmittable, since I think it's just confusing. If there's another alternative you'd like to see me create a PR for, feel free to suggest it.

[dtikhonov]

Does the English language have a suffix that means that something must be done ("ack$foo") rather than that can be done ("ackable")? What's $foo? 😖

[dtikhonov]

Based on this list of English suffixes, I propose that we use ackent instead of ack-eliciting. The suffix ENT means "one who performs/causes."

Thus, instead of

Packets that contain ack-eliciting frames elicit an ACK from the receiver within the maximum ack delay and are called ack-eliciting packets.

we will have

Packets that contain ackent frames elicit an ACK from the receiver within the maximum ack delay and are called ackent packets.

[mikkelfj]

resilient

Packets that contain resilient frames elicit an ACK from the receiver within the maximum ack delay and are called resilient packets.

unforgettable
https://www.youtube.com/watch?v=2HSt7LWsm-A

Packets that contain unforgettable frames elicit an ACK from the receiver within the maximum ack delay and are called unforgettable packets.

unmissable

Packets that contain unmissable frames elicit an ACK from the receiver within the maximum ack delay and are called unmissable packets.

robust

Packets that contain robust frames elicit an ACK from the receiver within the maximum ack delay and are called robust packets.

stateful

Packets that contain stateful frames elicit an ACK from the receiver within the maximum ack delay and are called stateful packets.

[dtikhonov]

@mikkelfj, my suggestion was in earnest.

[mikkelfj]

Mine was only half in jest. I kind of like resilient.