Implemented directives: variables_order&request_order

This also makes cli mode consist with PHP if S/E is not
in variables_order $_SERVER/$_ENV will not available in cli.

before the diff HHVM's default is variables_order=SEGPC and
request_order=GPC after the diff thoes directives becames:

  - variables_order=EGPCS
  - request_order=  and it will be the same as variables_order

@see <http://php.net/manual/en/ini.core.php#ini.variables-order>