Duplicate an assembly or a whole package

The second riser is the first riser with a different tag. The second floor's package is the first floor's with a few quantities changed. Until now that meant rebuilding the block line by line; the ⎘ button only worked on a single line.

• Assemblies. ⎘ on the assembly header copies the instance and every component line under it, named "… (copy)", directly below the original.
• Packages. ⎘ on the package header copies the package, its assemblies, and all its lines — nesting included — as a new package right after it.
• Lines now bring their nested children along when duplicated. And a copied sub line no longer stays tied to the vendor quote the original tracks: the copy keeps the number, the original keeps the link.

The copy is a snapshot. Change it freely; the original doesn't move.