Open copy window beside main one
Submitted by Reviczky Ádám János
Link to original bug (#409179)
Description
Add split view mode for browsing or compare the same document at different points (like Acrobat or Microsoft Office).
This means be able to have one evince window, inside splitted in two parts, booth parts have the same document opened, but can be scrolled differently. The horizontally split line is changeable by dragging.