Allow for multiple paths

[cflipse]

path-based requests are not particularly capable of handling requests for multiple ID values,
and when an HTTP relation is provided as a part of a pipeline, it may be necessary to provide the illusion of a single interaction.

In such cases, it's almost certainly preferable if the remote service provides some sort of multiple-id query interface, for performance reasons, but this is not always possible. This is a knife with a sharpened handle, but in some cases may be necessary...