Removes the output errorCode parameter (that is not currently used anywhere, except in testing code that gets but ignores it). Adds the options, variant and
idna_info parameters that are present in the Zend version of idn_to_ascii. Implement the new functionality required by these parameters by using the UTS #46 API, if
present.
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.