Thank you very much for the cleaning job.
I tried to put the panel in the location we used in the past, ( I know it is not anymore in the common files folder, but in user_AppData_Roaming_Adobe_XMP_Custom File Info Panels; but I don't know which number I need now for the sub-folder.) I thought I had the hang of it, but it does not show up in Photoshop CC2015.
I read the documentation, but it talks about new panels created from the SDK. The new panel does not show up along the other XMP metadata panels...
Where should I place it?