Add missing .desktop file, fix FTBFS.
Also adjust data/vboxgtk.desktop.in file.

Index: vboxgtk-0.5.0/data/vboxgtk.desktop.in
===================================================================
--- vboxgtk-0.5.0.orig/data/vboxgtk.desktop.in	2009-08-22 14:57:52.883442869 +0200
+++ vboxgtk-0.5.0/data/vboxgtk.desktop.in	2009-08-22 14:58:14.251445939 +0200
@@ -1,10 +1,8 @@
 [Desktop Entry]
-Encoding=UTF-8
 Name=VBoxGtk
-Comment=VirtualBox GTK+ interface
-Exec=vboxgtk
-Terminal=false
-StartupNotify=true
+Comment=GTK frontend for VirtualBox
 Icon=vboxgtk
+Exec=/usr/bin/vboxgtk
+Terminal=false
 Type=Application
-Categories=GTKi;Office;
+Categories=Emulator;Utility;
Index: vboxgtk-0.5.0/data/vboxgtk.desktop
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ vboxgtk-0.5.0/data/vboxgtk.desktop	2009-08-22 14:58:14.251445939 +0200
@@ -0,0 +1,8 @@
+[Desktop Entry]
+Name=VBoxGtk
+Comment=GTK frontend for VirtualBox
+Icon=vboxgtk
+Exec=/usr/bin/vboxgtk
+Terminal=false
+Type=Application
+Categories=Emulator;Utility;