Update p5-XSLoader to 0.16.

Changes from previous:
----------------------
0.16 - 2012.09.03 - SAPER
    - [CODE] Synced from bleadperl.
    - [DOC] CPAN-RT #77294: Fixed some spelling and grammer errors.
    - [TESTS] CPAN-RT #77557: Tests started to fail with Perl 5.15.5
    - [DIST] Perl-RT #114050: Added meta-information in Makefile.PL to
      reflect that the module is maintained by P5P.

(hiramatsu)