v2
- Added the thread_summary.query field.
+v3
+- Replaced message.filename string with a list of filenames.
+
Common non-terminals
--------------------
# (format_message_sprinter)
id: messageid,
match: bool,
- filename: string,
+ filename: [string*],
timestamp: unix_time, # date header as unix time
date_relative: string, # user-friendly timestamp
tags: [string*],