There is a runtime option to filter out notices and warnings,
but strict_warnings were left out. Bundle them with notices.
We raise a lot of strict_warnings; and when we fix hphpiCompat
(to match zend better) we will raise a lot more, so this could
matter.
This change is mostly for FB internal organizational reasons.
Building is not effected beyond the fact that the target now
lands in hphp/hhvm/hhvm rather than src/hhvm/hhvm.