Removed backfill_chunk_t::shard functions.
Got rid of backfill_chunk_t::get_region.
Removed complaint that array_t should not be in protocol_api.hpp.
Removed unused dummy protocol multistore_unshard function.
Removed way out-of-date protocol_api_notes.hpp file.
Removed some weird SAMRSIs in dummy_protocol_t that said things would have to be "implemented."  They ARE implemented??  I thought.