#13 Optional artist name field for sorting

[Erhhung Yuan]

In order for the alphabetical browsing of artists by last
name to work, the name currently must be written
as "Robinson, Smokey And The Miracles", for example.
It would be nice if the user can enter an optional name
when a new artist is created that would be used strictly
for sorting and categorizing by A-Z. So the user will
see "Smokey Robinson And The Miracles" but find the
artist under R, as would be expected.