Modify tests to add the all zero data case.

Peter Robinson reported a divide by zero bug if all of the data for a
line graph was zero. Add tests for all Sparkline types to test this
case.
Handle all zero data case.

If all of the data is zero for the Sparkline, the "y range" is
calculated to 0. The range is used as the denominator when calculating
the scaling factor, so it obviously fails.
The Line and Area graphs use the code in SVG::Sparkline::Utils to do
this calculation. The Bar graph does it directly.
Add missing Change entry for release 0.36.
Modify Changelog to CPAN::Changes::Spec format.
Update version, copyright, and contact email

Since the module has been stable for a while (except for this bug), I'm
upgrading it to version 1.00.
Updated the copyright date to 2013.
Corrected the email address to the CPAN redirection address.