This commit changes the local timezone calculation to use tm.tm_gmtoff,
and falling back to calculating it manually from the output of strftime
when tm_gmtoff is not a member of struct tm.
This also fixes the tests so that they are no longer expected to fail.
Fixes#20.
Prior to this change, the tests were using the automake simple test
harness. The limitation was that for each set of test cases (e.g.
timezone tests), even if one test failed, it would report every test in
that set as failed. Migrating to TAP allows fine-grained reporting on
every single test case, and allows better investigation into checking
which individual tests failed.
This change also updates the timezone tests to explicitly mark the ones
that check when the timezone is Pacific Daylight Time as expected to
fail. It also updates the clock tests to improve the formatting of the
test case identifier.
nirenjan