combined proposal for 7586, 7588, and 7828

Among other things, this proposal discharges my obligations under 
ACTION-113 <http://www.w3.org/2002/ws/ra/tracker/actions/113>.
    - gp
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Add the following after the second paragraph of 
[Body]/wse:Subscribe/wse:Expires and before 
[Body]/wse:Subscribe/wse:Expires@min.

    The value of the wse:Expires element as well as those of its min and
    max attributes MAY be either a duration (xs:duration) or a specific
    time (xs:dateTime). Event Sources and Subscription Managers MUST
    accept duration values and MAY accept specific time values. Upon
    receiving a request that contains specific time values, an Event
    Source or Subscription Manager that does not support such values
    MUST fail the request and generate a wse:UnsupportedExpirationType
    fault.

    The value types in a wse:Expires element MAY differ among the
    element and its attributes. For example, the element value may be a
    duration while the max attribute may be a specific time. Regardless
    of the value types, it must be true that wse:Expires/@min <=
    wse:Expires <= wse:Expires/@max as interpreted by the Event Source
    or Subscription manager at the time the wse:Subscribe request is
    processed. If this is not true, the request MUST fail and the
    receiver MUST generate a wse:InvalidExpirationTime fault.

    If a Subscriber chooses to use specific time values in a request, it
    is RECOMMENDED that these values include a time zone component.
    Specific time values that lack a time zone will be interpreted in
    the local time zone of the Event Source or Subscription Manager.

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Make the following changes to the description of wse:Granted Expires*

[Body]/wse:SubscribeResponse/wse:GrantedExpires*

    The expiration time assigned by the eEvent sSource. The expiration
    time MAY be either an absolutespecific time or a duration but
    SHOULDMUST be of the same type as the requested expiration (if
    any)wse:Expires element of the corresponding request. If the
    corresponding requestion did not contain a wse:Expires element, this
    element MUST be a duration (xs:duration).

    When expressed as a duration, the wse:GrantedExpires element
    designates a time interval that began at the moment the Subscription
    is created. Although this specification cannot dictate when, during
    the processing of a Subscribe request, a Subscription is created,
    the Event Source MUST start the expiration interval at or before it
    transmits the wse:SubscribeResponse message.

    If this element does not appear, then the subscription will not
    expire. That is, the subscription has an indefinite lifetime. It MAY
    be terminated by the subscriber using an Unsubscribe request, or it
    MAY be terminated by the event source at any time for reasons such
    as connection termination, resource constraints, or system shut-down.