Differential Revision: https://developer.blender.org/D298 Allows users on Windows to enter UNC paths in the filebrowser and to link to .blend files on a UNC path. Functionality is limited still, we can't browse the network yet and have no support to check user rights so far. What works: - enter an UNC path in the file browser manually or via copy/paste - navigation within the UNC share subfolders - link to a file on a UNC share What does not (yet) work: - browse the network for computers and shares - browse to a folder that requires entering user credentials Contributors: Rob McKay - original patch Campbell Barton - style fixes Reviewers: Campbell Barton, Brecht van Lommel