Support wildcards in Time patterns

* Discontinue support for TimePattern-TimePattern comparisons
* Call 'super' on compare when passed object does not respond to to_time
* Rewrite test suite to match new behavior
Merge pull request #15 from migl/wildcards

Support wildcards in Time patterns
Integrate DayOfWeek into TZ blocks

* Remove Time parsing ability from DayOfWeek matcher
Merge pull request #16 from migl/day_of_week

Integrate DayOfWeek into TZ blocks
Improve TimePattern equality operator
Merge pull request #17 from migl/time_pattern_equality

Improve TimePattern equality operator