local: factor UNCPath into lib/file

lib/file/unc.go

@@ -0,0 +1,10 @@
+//+build !windows
+
+package file
+
+// UNCPath converts an absolute Windows path to a UNC long path.
+//
+// It does nothing on non windows platforms
+func UNCPath(l string) string {
+	return l
+}