Remove "ignore" state from the git.git-authors

Remove the "ignore" state for authors.  I'm not sure what the original thinking here was, but it doesn't make much sense.

These people were added based on the state of git.git when their names were added.  They may have made subsequent contributions which should *not* be ignored.  Further, whether a change is "interestingness" is a strange judgement call.

The whole damn thing doesn't make any sense; somebody is either of the "always ok", "never ok" or "always ask".