default interface/operation/@pattern

We would like to see the "pattern" attribute of "operation" elements
defaulted based on the contained <input> and <output> elements for
those patterns where that is unambiguously possible. The component 
model will continue to have the current behavior - this is only
a syntactic convenience.

Requiring all users to remember the values of the pattern URIs 
when the value is patently obvious from the <input> and/or
<output> elements makes the language overly cumbersome with 
no value. We would like this extra complexity removed.

Note that this is only a default - if someone else were to define
a pattern with only one <input> and no <output>s then they can
still live happily with the user explicitly setting the value.

Sanjiva, on behalf of IBM.