* src/misc/objects.c: implemented the FIND_CHILD mode for vlc_list_find().

* src/misc/objects.c: implemented the FIND_CHILD mode for vlc_list_find().
   vlc_object_get() now increments the refcount of the object so you'll need to release
the object at some point.
* src/misc/variables.c, ALL: var_Change() with VLC_VAR_GETLIST now returns a vlc_value_t
which points to a vlc_list_t.