The new macros, and indeed the previous macros, do not work on
Perl prior to 5.19.0 because the bug is actually how in Perl itself
handles the locale bits.  So we just go back to effectively always
saving the locale.  Resolves:

  https://rt.cpan.org/Ticket/Display.html?id=91987
$VERSION++ for CPAN release.
Isolate the locale testing to make it easier to deal with on Android.
On Android, strip out 'use locale' so that it doesn't fall over.