mwext-{ext-name}-lint: use-zuul instead of use-zuul-for-mwext

No need to put it in extensions/ only to then have to override the target in ant
Also switch it to use the phplint builder, since it was now equal to it

Change-Id: Ic544c0cc0cd56126b5f29dd29b61aa85f4830922
phplint macro: Use lint.php instead of php -l

Also, as part of switching away from Ant and php -l, fixed the
determination of which files to line.

Problems solved:
* Checked HEAD^ instead of HEAD^..HEAD (though usually the same,
  the semantics are different, working copy including unstaged
  vs committed HEAD)
* git --name-only returns names escaped by default (\t, \n, \\, \")
  and if any such escaped occurred, it wraps the name in quotes.
  The grep did not account for this with "\.(php|php5|inc|phtml)$"
  which skipped files that contained any escaped characters.
  The logic ant did after with applying arguments, also did not account for them
  already being escaped.
  Switched to passing -z to git, which disabled escaping and uses a null byte
  instead of new line as separator.
* git --name-only includes renamed and deleted files. Unlike ant with php -l,
  code-utils/lint.php throws an error when passing the path of a file that does
  not exist. Fixed by using a diff-filter that only includes [A]dd, [C]reate,
  and [M]odified.

Note, we have to use php bin/lint.php instead of bin/phplint because we need
to pass -dextension=parsekit.so because the php5-parsekit package doesn't
create an /etc/php5/conf.d file.

Change-Id: I68e036ca94126405ebf4ecceb4b7008f493a36ed