Implement copy-pasting of shapes!

This patch implements the following:

1) The shapes can be copy/pasted inside Krita
2) The shapes can be copy/pasted Krita->Inkscape
   (reverse does not yet work)
3) There are two shortcuts (reverse to Inkscape :( )
   Ctrl+V paste at original position
   Ctrl+Alt+V paste at cursor position

CC:kimageshop@kde.org