Ease clients' handling of split-fileset operations.

[mtbc]

#100 (comment) reminds of how, when a user specifies a graph operation like chgrp with a partial fileset, then it is for clients to try again with all the fileset's images (or indeed the fileset itself) targeted. It would be quite workable for requests to simply offer an "include whole fileset" option that, say, causes a,

graphPolicy.setCondition("whole_fileset");

and, before the policy rules like,

<bean parent="graphPolicyRule"
    p:matches="Fileset[I].images = I:[E]"
    p:changes="I:[I]"/>

<bean parent="graphPolicyRule"
    p:matches="F:Fileset[E]{i}.images = [I]"
    p:changes="F:{r}"/>

include an earlier rule like,

<bean parent="graphPolicyRule"
    p:matches="$whole_fileset, F:Fileset[E].images = [I]"
    p:changes="F:[I]"/>

(In general, ome.services.graphs offers a lot of hooks that omero.cmd.graphs could use for effecting all manner of behaviors.)