templatekw: fix extras, manifest and showlist args (issue1989)
Removing the explicit parameters from keywords signature is easier than copying
and reproducing the original argument list.
adding a/b/c/d/x
adding a/b/c/d/y
adding a/b/c/d/z
moving a/b/c/d/x to z/b/c/d/x
moving a/b/c/d/y to z/b/c/d/y
moving a/b/c/d/z to z/b/c/d/z