Add bindings for GInitiallyUnowned

This will never directly appear anywhere in use apart from defining new
subclasses that inherit from GInitiallyUnowned directly, i.e. classes
that use floating references.

This should only really ever be used for compatibility with C code.
Floating references cause hard to debug problems and are meaningless for
bindings.

Author: sdroege

src/lib.rs

@@ -104,6 +104,8 @@ pub use object::{
     Object,
     ObjectExt,
     ObjectClass,
+    InitiallyUnowned,
+    InitiallyUnownedClass,
     WeakRef,
     SendWeakRef,
 };

src/object.rs

@@ -1303,6 +1303,14 @@ impl ObjectClass {
     }
 }
 
+glib_wrapper! {
+    pub struct InitiallyUnowned(Object<gobject_ffi::GInitiallyUnowned, gobject_ffi::GInitiallyUnownedClass, InitiallyUnownedClass>);
+
+    match fn {
+        get_type => || gobject_ffi::g_initially_unowned_get_type(),
+    }
+}
+
 pub struct WeakRef<T: ObjectType>(Box<gobject_ffi::GWeakRef>, PhantomData<*const T>);
 
 impl<T: ObjectType> WeakRef<T> {