Support for teracopy.

Support for teracopy shell extension on file copy/move to override internal file copy.

The scroll lock key override to disable/enable teracopy does not work.

Signed-off-by: dbosst@gmail.com <dbosst@gmail.com>

Note: Lightly tested OK on Windows XP (checked copy/move across drives & network shares).  Don't have a clue yet how to get the scroll-lock disable feature of teracopy working.