- It's not *exactly* ISO 8601 which doesn't seem to support
subseconds, but subseconds are very important to us and
most things that support ISO8601 seem to also support subseconds
in the way I'm implemented it.
- Formatters have been abstracted similarly to readers and writers now.
- The Ascii writer has a new option for writing out logs as JSON.
- The Ascii writer now has all options availble as per-filter
options as well as global.