NEW ISSUE: Reorder spec sections

Title: Reorder spec sections

Description:

The current order in which the RM spec talks about the protocol elements
is:

        Sequence header

        SeqAck header

        ReqAck header

        CreateSequence

        TerminateSequence

        CloseSequence

I'd like to reorder them based on how we actually
expect people to use them.

Justification:

Helps in understanding the spec.

Target: wsrm spec

Type: design

Proposal:

Change the order to be:

        CreateSequence

        Sequence header

        ReqAck header

        SeqAck header

        CloseSequence

        TerminateSequence

Related issues: none