Before this commit, the existing alignments were `LEFT` and `RIGHT`,
which added the `padding` character to the right and left just before
finishing formatting. However, if `padding == '0'` and the alignment is
to the right, then the padding character (digit zero) was added after
the sign, if one is present.
After this commit, the special case for `padding == '0'` is removed,
and the new justification `NUMERIC` adds the padding character like
the justification `RIGHT`, except after the sign, if one is present.
(Space, for the `SPACE_MINUS` sign mode, counts as the sign.)
Catherine
1780e2eb1e