Add a dialog to change the source of clone layers
From https://invent.kde.org/kde/krita/merge_requests/12
This commit adds an action named Set Copy From' to the context menu of the Layers Docker, if one or more clone layers are selected. The action pops up a dialog that can change the
Copy From' property of
selected clone layers.
The dialog previews the changes to these layers. If there is any change to the document when the dialog is open, the changes in the dialog will be applied and the dialog closed.
Edited by tusooa the west wind