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.