Fix for #2511
Merge branch 'next' of github.com:rethinkdb/rethinkdb into next
Fix for #2511
Merge branch 'v1.13.x' into next
Made unsharding rget_read_t initialize the global_optargs of the env_t.
Merge branch 'sam_2525' into v1.13.x
Merge branch 'v1.13.x' of github.com:rethinkdb/rethinkdb into v1.13.x
Merge branch 'v1.13.x' into next
Merge branch 'next' into sam_2156_env_stuff