Implement partitioned registrations on client

[ecorm]

Implement partitioned registrations, as per the advanced spec.

[ecorm]

Client requirements:

• HELLO.Details.roles.caller.features.partitioned_rpc|bool := true
• HELLO.Details.roles.callee.features.partitioned_rpc|bool := true
• CALL.Options.runon|string := "all" | "any" | "partition"
• CALL.Options.runmode|string := "gather" | "progressive"
• CALL.Options.rkey|string
• If runmode == "gather", the callee will receive all results in a single list in the RESULT reply.
• If runmode == "progressive, the callee will receive progressive results (RESULT.Details.progress == 1)

The behavior is currently incomplete in the spec regarding what happens if any of the invocations return an ERROR.

The description for CALL.Options.runmode == "partition" and CALL.Options.rkey is incomplete in the spec. Presumably CALL.Options.rkey is a way for nodes to registers themselves as a group under some common key.

This feature currently seems unstable.

[ecorm]

The spec for this feature is still in "sketch" mode. There is no extra logic required to support this feature client-side in CppWAMP. The various CALL.Options can be set manually via the wamp::Options interface.