Handle platforms without LC_ALL/setlocale defined.

On Android (and any perl built with -Ud_setlocale), Template::Plugin::Date
and its tests cause errors because neither setlocale() nor the
locale-related constants are defined, so we need
to protect those calls by checking what %Config has to say.
Merge pull request #34 from Hugmeir/master

Handle platforms without LC_ALL/setlocale defined.