Rename master_stage_protocol.c

[aamederen]

Since we are planning to deprecate and later get rid of \stage, after COPY is included in Citus, I think we need to get rid of "stage" in master_stage_protocol.c.

[ozgune]

@aamederen, I wanted to drop in a quick note.

We borrowed the concept of staging data into the cluster from Hadoop; and several customers use the functions in this file irrespective of \stage. Do you have a file renaming proposal in mind?

[aamederen]

I have thought that the stage in master_stage_protocol is the same as \stage so since \stage is going as should master_stage_protocol. Since these functions are shard-related functions, one possibility could be master_shard_protocol.

[ozgune]

@aamederen -- master_shard_protocol feels a bit generic to me. Since stage also refers to the concept of uploading data into the cluster, I'm leaning towards closing this issue for now. Any strong reservations?

[aamederen]

@ozgune No I don't have any. Let's close it.