Revert the change for strict mode options in v8.0.0-beta.1 to allow overrides to disable some options, not only to enable.
These strict mode options are available:
strictSchema - new, equivalent to strict: true in v7, default true
strictNumbers - reinstated from v6, but with default true
strictTypes - same as in v7, default "log"
strictTuples - same as in v7, default "log"
strictTuples - same as in v7, default false
Option strict sets all options above to the same value.