New test - parse another iCal without clearing object.

This one tests that we can parse multiple iCal feeds onto a single Google
Calendar without clobbering what was there.

In other words, check that this big refactoring, which came about as a result of
Issue #8, actually does fix Issue #8.
Add expected output from allday.ical
fix typo in comment
Another comment typo
Test with a non-DST-timezone.

When we pass DateTime objects to Net::Google::Calendar::Entry's when() method,
it automatically converts them to UTC; we want to test that the result is
correct.

Using a timezone that doesn't observe DST means the result will always be the
same, rather than us failing our tests in the summer/winter :)
Missed updating this datetime from last commit
Test titles to make output a bit clearer
Set the all-day flag if start & end are 00:00:00

This is a bit hackish perhaps; might be better to fetch the raw dtstart/dtend
and inspect for absence of a time component.
Expect the all_day flag, now it works :)
Add DateTime::Format::DateParse as a prereq.

Swapping DateTime::Format::ISO8601 for DateTime::Format::DateParse.

Nod to Pizentios on Freenode/#perl for the recommendation.