Fix tundra.file:reflect to work correctly when $file argument is a
directory
Rename tundra.timezone:self backing Java method from getDefault to
self
Add support for custom datetime patterns to tundra.timezone:* services
Fix tundra.timezone:get to not return GMT zone when $id is an
unknown time zone; closes #45
Change tundra.timezone:get to treat $id = 'Z' and an alias of 'UTC';
closes #46