* make 'insets' const.
* make 'insets' not pass in a KoShape; there is no way the insets
  can change based on the shape passed in.
* rename setVisibility -> setVisible so its a match with isVisible
* fix bug in insets() when the shape is invisible the insets are
  set to zero, not left untouched.

svn path=/trunk/koffice/; revision=1072431