Copy/Work Changes

Hi,

This includes a number of changes to the works and copies screens.

- Use bibLevel to determine the kind of work it is.
- Give a good reason why copy cannot be displayed ( @shuangzhou this one's for you. ;-) )
- put DCM legacy data in a different panel
- separate the CopyOf/Parent fields to make them more obvious.

Many of these changes have been suggested by other developers.

Huw