Removed rdb_read_visitor_t::get_env, made "Perform read on shard." be per-method.
Made rdb_read_visitor_t::extract_event_log not depend on ql_env lifetime.
Dropped the broken RVALUE_THIS from rdb_read_visitor_t::extract_event_log (instead of fixing the caller).
Made rdb_read_visitor_t construct an env_t only in rget_read_t.
Added apologetic comment about trace and dump_event_log_t.
Removed use of init_optargs in rget_read_t.
Moved "Perform write on shard" profiling on each method in rdb_write_visitor_t.
Only constructed env_t for batched_replace_t in rdb_write_visitor_t.
Removed the unused global_optargs_t::init_optargs.
Made profile::trace_t be constructed outside of the env_t.
Made profile::trace_t be constructed outside the rdb_read_visitor_t and rdb_write_visitor_t.
Deduped start_read and start_write lines that had been temporarily duplicated (now that profile::trace_t is created outside of env_t).
Merge branch 'sam_gchpaco_2059' into gchpaco_2059

Conflicts:
	src/rdb_protocol/configured_limits.cc
	src/rdb_protocol/store.cc