Linked XRD Processing Rules

[Eran Hammer-Lahav <eran@hueniverse.com>]

The questions we need to answer in order are:

- Is there a need for general purpose processing rules to link one XRD to other XRDs?

- If yes, is a #replace directive enough, or do we need #include?

- If yes to #include, do we need it today or can we defer it to another spec with more advanced processing rules protocols can use?

EHL