"alt" does not render nicely in Jazz chord symbol style

Ubuntu Studio 14.04, GIT commit: 1514034

1) new score, Jazz Lead Sheet templatre
2) enter chord symbols: C7sus C7alt

Result: "alt" is noticeably larger than "sus"

There is a predefined glyph in MuseJazz for "sus", not for "alt". We could either add one, or scale the text down for this particular token.