Text for metrics

[Fred Maciel <Fred.Maciel@hds.com>]

William,

     Here are the correction for the text on the metrics (Igor, please
double-check). All are in MUWS part 2.

(1) On "(MetricAttributes)/ResetAt", in line 787, **erase** the following
text:

"If a reset capability is supported for the metric, this attribute MUST be
included with the metric property. If this metric can not be reset or a
reset capability is not supported, this attribute MUST NOT be present.
Properties having a TimeScope of PointInTime MUST NOT include this
attribute."

(2) On the definition of Interval in line 836, **add** the following text to
the end or to the second sentence. It's not really needed, but since this is
mentioned explicitly in MOWS we should add it to MUWS also. [I don't
remember us deciding in which circumstances we add it, or the semantics of
it, so it's safe to leave it like this for now].

The ResetAt attribute MAY be reported.

(3) The definition of SinceReset in line 844 becomes:

SinceReset - the value of the metric is collected since reset, or since the
manageable resource started collecting metrics data. In this case the
Duration attribute MUST NOT be reported with the metric property, and the
ResetAt attribute MUST be reported.

Regards,

Fred Maciel.