[improvement] Added artist column to Zune Desktop tracks list. Shows when tracks have different song artists.

[amaid]

• Added a new column on track collection on zune to display artists.
• The artists are only displayed if a track has more than one artist excluding the target artist itself.

Multiple_artists_On_Tracks.mp4

[Arlodotexe]

Looks like it's showing when it shouldn't -- since all the names are the same in the screenshot below, we need to hide the column.

Repro:

1. Set up a file based core (I had both taglib and file properties enabled)
2. Select an artist
3. Select an album
4. Observe the bug

Alternate repro:

1. Set up a file based core
2. Once the zune shell loads, from the artist page, select any album
3. Observe the bug

[Arlodotexe]

There's still a lingering bug with this.

1. Set up a file core
2. Load the Zune Desktop shell
3. Go to the collection view
4. Select an album first
5. Observe the bug. Artist column is showing when it shouldn't, and shows double artists.

The problem can also be seen on any album in the "Albums" tab.

[Arlodotexe]

I also managed to get this exception:

1. Set up a file core
2. Load the Zune Desktop shell
3. Go to the collection view
4. Switch between albums during a file scan until the crash occurs.

[amaid]

I also managed to get this exception:

1. Set up a file core
2. Load the Zune Desktop shell
3. Go to the collection view
4. Switch between albums during a file scan until the crash occurs.

Fixed

[amaid]

There's still a lingering bug with this.

1. Set up a file core
2. Load the Zune Desktop shell
3. Go to the collection view
4. Select an album first
5. Observe the bug. Artist column is showing when it shouldn't, and shows double artists.

The problem can also be seen on any album in the "Albums" tab.

Fixed

[Arlodotexe]

Linking #129