Initial commit of chromehang export
Include a local copy of symbolicate.py
Trim down the payloads before writing them out

Instead of writing them out and discarding pieces during symbolication,
discard them now to save on I/O.
Add a 'date' parameter, don't expect historic fmt.

Remove some of the special cases for the old Telemetry format, and
add "submission date" as a parameter.
Merge branch 'bug931906'