It makes no sense to begin our tracked nested level at
'1' then later require a '1' to be subtracted from the
level as artwork and indentation is added for display.

By beginning such tracked levels at zero, we can avoid
the need to adjust it & use it directly in a snprintf.

[ this commit parallels a patch in our newlib branch ]

Signed-off-by: Jim Warner <james.warner@comcast.net>