Provider returns requestID.

[Gary P Cole <Gary.P.Cole@Sun.COM>]

SPML 1.0 says that the requestor must generate a globally unique value 
and pass it as the value of the 'requestID' attribute of SpmlRequestType.

I believe that the *provider* should generate and return 'requestID' in 
its *response*.  The provider's response should be synchronous.

If an operation that was requested as synchronous can be converted to 
asynchronous execution at the provider's initiative, then the provider 
*must be able* to return a 'requestID' that the requestor can use to 
follow the operation.

Even when the request specifies "execution='asynchronous'", I think it 
makes more sense for the provider to return the requestID. It is much 
easier for the provider (than it is for the requestor) to generate a 
value that is globally unique in the provider's namespace.

A synchronous response from the provider acknowledges each request and 
(if the operation is asynchronous) returns a requestID that the 
requestor can supply to a 'status' or a 'cancel' request.  If there is 
any immediate error (for example, if the provider does not support 
asynchronous execution or if the request is malformed), the requestor 
can determine this immediately from the response (without having to poll 
for a result).

gpc