Disable Gtk+ 3 client side decorations (CSD)

 gtk3-nocsd LD_PRELOADs a small library to disable the client side
 decorations (CSD) of Gtk+ 3.
 .
 Since Gtk+ 3.10, its developers added a so-called header bar or custom
 title bar. With this and the client-side decoration, the original
 title bar and window border provided by the window manager are
 disabled by Gtk+. This makes all Gtk+ 3 programs look like alike, but
 have different handling from other windows on non-GNOME desktops. Even
 worse, this may break some window manager or compositors.
 .
 Unfortunately, there is no reliable way of turning off CSDs in Gtk+
 directly. This library makes this possible.