[NEW ISSUE] Add Max Msg Num to CSR

Title: Add Max Msg Num to CSR

Description:

The createSeq/createSeqRes handshake already passes back the AckInterval
which can be useful information to the RMS.  Knowing the max msg number
that the RMD will support could also prove useful since not all impls will
support the large # we mention in the spec.  

Justification:

By the RMS knowing this information it may choose to use it to avoid getting
the Message Number Rollover Fault and be able to deal with this situation
in a much more graceful manner.

Target: core design

Proposal:

On the CSR add as an optional sibling to AckInterval:

Pseudo-schema (changes in bold):

<wsrm:CreateSequenceResponse ...>

    <wsrm:Identifier ...> xs:anyURI
</wsrm:Identifier>

    <wsrm:Expires> xs:duration </wsrm:Expires>
?

    <wsrm:AcknowledgementInterval Milliseconds="xs:unsignedLong"
... /> ?

    <wsrm:MaxMessageNumber> wsrm:MessageNumberType
</wsrm:MaxMessageNumber> ?

    <wsrm:Accept ...>

        <wsrm:AcksTo ...>
wsa:EndpointReferenceType </wsrm:AcksTo>

        ...

    </wsrm:Accept> ?

    ...

</wsrm:CreateSequenceResponse>

and add...

/wsrm:MaxMessageNumber

This element, if present, specifies the largest message
number that the RM Destination will accept for the specified Sequence.
If omitted, the implied value is 9,223,372,036,854,775,807.

Update schema accordingly.