git notes: notes

Just a quick note that the new notes feature can break things that parse git log. For example a parser that assumes it can split the log on blank lines to separate the header and commit message, can easily become confused by the new blank line before "Notes:".

Might be worth documenting in release notes, maybe too late now though. But really, it's all good, notes are a great feature.

PS, Has anyone thought about using notes to warn bisect away from commits that are known to be unbuildable or otherwise cause bisection trouble?