Bring RDMAObjectStore + FullCacheStore up to date

[TylerADavis]

At the moment, there is no code that relies on these two stores, and as such they have not been compiling. As a result of this, they have slipped under the radar when the new interface was implemented. They should be brought back up to date with the new interface.

[jcarreira]

I think these are mostly old software artifacts lying around. Let's come back to this later.