Put client fails if return checksums are requested and a checksumpillar is involved

The current put, replace and delete clients will try to request returnChecksums (which will typically be non-default) from all pillars if this has been specified in the call. As checksum pillars will be unable to deliver this, the request will fail.

The client should therefore avoid requesting (non-default) returnChecksums from checksumPillars. ChecksumPillars can be detected by their PillarChecksumSpec value in the IdentifyResponse. These should then not have the ChecksumRequestForNewFile element specified in the request.