* anders/diameter/sctp/OTP-10889:
  Make unordered delivery configurable

Changing the default in the parent commit is possibly a bit dangerous,
even if the motivation still holds. Take a step back and make unordered
delivery a matter of configuration, without changing the default:
configuration is {unordered, boolean() | pos_integer()}, with false the
default, and N equivalent to OS =< N, where OS is the number of outbound
streams negotiated on the association in question.

A user can mess with this by configuring an sctp_default_send_param of
their own, but unordered sending is them from start, not only after the
second message reception.

* anders/diameter/sctp/OTP-10889:
  Send unordered on all outbound diameter_sctp streams
  Delay rotation of diameter_sctp outbound streams
  Exercise unordered delivery in traffic suite
  Use unordered delivery on a lone outbound stream in diameter_sctp

There's no reason for sending ordered since request handling is
concurrent: different processes handling incoming requests can't know in
which order they were received on the transport, and different processes
sending requests can't know the order in which they're sent.

For the same reason as unordered delivery is delayed in the grandparent
commit. Delivery is ordered only within a stream, so until a second
message is received from the peer, there's no guarantee that a second
outgoing request won't be received before the initial capablities
exchange message. Rotation begins upon reception of a second message
from the peer, messages being sent on stream 0 until then.

* anders/diameter/config_consistency/OTP-14555:
  Let strict_mbit and incoming_maxlen be configured per transport
  Let a service configure default transport options
  Rename type evaluable -> eval

* anders/diameter/loopback_any/OTP-14544:
  Use loopback/any config in examples suite
  Handle loopback/any as local address in diameter_tcp/sctp