fix github issue #238 - 'scores' option

fix github issue #238 - 'scores' option

Fixes #238

For the three fields in the 'scores' option's argument: top, around,
and own, if any was separated from preceding one by space(s) rather
than slash and lacked a count prefix, the argument parsing skipped
over it.  So "10t/3a/o" and "10t 3a 1o" worked but "10t 3a o" ignored
the 'o'.  The issue report was about 'own' but there's nothing special
about 'own' itself; just that it doesn't warrant a count prefix and is
usually last (in other words, normally preceded by one or both of the
other two) so more likely to trip over this.

[I thought there was another report about 'scores' misbehaving (from
quite a while ago) but couldn't find one.  If it exists, it might have
been about the same thing.]