More bug fixes/cleanup.
Changes:
- Changed default 'Done' message to 'Thank You'.
- Player: disable repeat button also when play button is disabled.
- Raffle Games: background is white rather than default background color.
- Import M3U: Don't rebuild database if no files are copied.
- Import M3U: Now allows editing of the 'import prefix'.
- Bug: Fixed typo/crash in Export for CD (introduced in 2.18).
- Bug: Import M3U: Fixed status message not showing.
- Bug: Import M3U: Would crash when the song selection window had data displayed.