Applied the jd multiset version of pass_back_superblock and find_keyvalue_location_for_write.
Wrote out much of batched writes implementation, but not the rdb_batched_set function.
Implemented a seemingly correct implementation of the rdb_batched_set function, leaving us with the task of hooking up the query language.
Added batched_replaces_t, everything except hooking _that_ up to the query language code.
Adjusted some whitespace in val.cc.
Replaced replace with variadic templated replace.
Fixed compilation problems in val.cc.
Added batched_replace function in val.hpp.
Replaced variadic table_t::replace function.
Petty reshuffling of code in writes.hpp.
Added datum_stream_t::next_batch with next_batch_impl having a default implementation.
Implemented array_datum_stream_t::next_batch_impl.
Made inserts use batched stuff and limited array stream batches to 100.
A whole bunch of debugfs for segfault debugging.
Merge branch 'ql-refactor' into sam_457
Fixed superblock ownership bug in rdb_batched_set and rdb_batched_replace functions and the protocol_write interface.
Merge branch 'next' into sam_457

Conflicts:
	src/rdb_protocol/val.cc
Made batched_replaces_t and batched_writes_t use a std::vector<std::pair<int64_t, ...> > instead of a std::vector<...> for sharding/unsharding.
Made the batched operation responses carry the int64_t for resorting upon unsharding.
Made unsharding implemented, possibly got batched reads and writes working.