A timestamp is import meta-data, add option to use a different field

[Omnifarious]

For example, you could easily add a newline + a 4 byte base64 string to the commit message, and that would probably be enough for a 5 hex digit collision for the revision hash, and it would just add a few random characters to the end of the commit message, not affect something as interesting and useful as the timestamp.

[mattbaker]

Hmm, yes! What if we just appended mixes of invisible characters to the commit message?