Re: item.cc: make is_non_musical() conform to its name (issue 5373048)

[mtsolo]

LGTM.

I like the fact that this brings the function name in line with the
function's function - it'll make it easier on future users of the
function to understand what's going on.

I won't have time to test it today, but I'm assuming that the change
doesn't have adverse effects in other places where non_musical is used.

Cheers,
MS

http://codereview.appspot.com/5373048/