Music group roster

[cjcodeproj]

The <catalog> element for a song or album should support an optional roster element listing members of groups.

Example.

<catalog>
  <roster>
    <group>
       <name>Vam Halen</name>
       <member><gn>Eddie</gn><fn>Van Halen</fn></member>
       <member><gn>Alex</gn><fn>Van Halen</fn></member>
        <member><gn>David Lee</gn><fn>Roth</fn></member>
       <member><gn>Michael</gn><fn>Anthony</fn></member>
    </group>
  </roster>
</catalog>

The purpose of the element is to establish group membership/affiliation and structure; performance information as to which member is covering what instrument is to be defined elsewhere. The type will be simple in that it allows for an optional name and member list of one or more members.

It is also possible that the same defined type could support other elements that are more descriptive, such as 'or`.

See also #130