(nsxiv): make key handler more concise and update reference to wallpaper set script

.config/nsxiv/exec/key-handler

@@ -1,28 +1,16 @@
 #!/bin/sh
 
-copy() {
-	file="$1"
-
-	file_ext="${file##*.}"
-	case "$file_ext" in
-		"png")
-			copy_path="$file"
-			;;
-		*)
-			file_name="${file##*/}"
-			file_base="${file_base%%.*}"
-			copy_path="/tmp/copy_$file_base.png"
-			;;
-	esac
-
-	xclip -sel clip -t image/png "$file"
-	notify-send "nsxiv" "Copied <b>$copy_path</b> to the clipboard."
-}
-
-while read -r file; do
-	case "$1" in
-	w) wallpaper "$file" ;;
-	e) gimp "$file" ;;
-	y) copy "$file" ;;
-	esac
+while IFS= read -r file; do
+    case "$1" in
+    w)
+        wallpaper-set "$file"
+        ;;
+    e)
+        setsid -f gimp "$file"
+        ;;
+    y)
+        xclip -sel clip -t image/png "$file"
+        notify-send "nsxiv" "Copied <b>${file##*/}</b> to the clipboard."
+        ;;
+    esac
 done