Replaced undef on hash elements within Natural/Base.pm with delete.
Changed 'time_zone' parameter's value in calls to DateTime->now()
with 'floating' instead of 'local'. This should function as fix
to failures reported on MSWin & Cygwin platforms according to
[Dave Rolsky urth@autarch.org].Due to an unlocalized signal warning handler, uninitialized
warnings in code which either required/use'd DateTime::Format::Natural
were being supressed. The handler has been commented out (and left in
for debugging/development purpose) and replaced by an according
'no warnings' statements in both Natural.pm & Natural/Base.pm.