File name change undo fails to update tag box

[rjkroege]

The following sequence:

• open a file
• modify only its filename
• Undo

Successfully undoes the file name change but leaves the tag box set to
the "file is modified" state. I deem this incorrect. The box should
rreturn to noting that the file has not been altered.

[rjkroege]

No longer happens.