ENH: All unimplemented copy constructors and assignment operators made private so that errors will show up at compile time instead of link time.  Since they are not implemented, they can never be called, so they should be private instead of protected.

A new CVS repository was created on 2001-04-26 to fork VTK during
transition to a new source tree layout.  The new repository was created
using server-side symlinks referencing files in the original repository
to preserve per-file history.  This commit was manufactured during
conversion from CVS to represent the fork as a branch.