Generator
~~~~~~~~~
+ Support boxed types
+ Expose GTK properties
+ Implement '#line' pragma directives for debugging
+ Support for some custom arg types like GdkRectangle*
+ Allow for templatization of PHP_METHOD() declarations in overrides
+ Interfaces
* Pointers

Base Functionality
~~~~~~~~~~~~~~~~~~
+ Support signal connection and closures
+ Custom boxed types
+ Make error messages display Class::Method() instead of just method name
* Some classes need to be coded in C entirely, see gtk-types.c
* Interfaces
* Pointers
* Atoms
* Implement __gtype, __doc, and other special properties, if possible
* Deal with clone() handler in Zend
* Find out why PY_TYPE_OBJECT is boxed
* Maybe use zend_call_function() instead of call_user_function_ex() to take
  advantage of function call cache
* Construction of arbitrary GObjects() via argument lists

Classes and Functions
~~~~~~~~~~~~~~~~~~~~~
* GtkListStore
* GtkTreeModel
* GtkTreeStore
* GtkTreeView
* GtkCellRenderer

Fix
~~~
* StyleHelper does not implement handlers that ZE2 _requires_ right now. Need
  to change either ZE2 or StyleHelper.


Thoughts on reference counting and wrappers
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. We should probably not ref the GtkWindow/GtkInvisible after construction.
   It leaves a hanging reference around and the window will not get destroyed by
   Gtk+. The proper way to destroy the toplevel window is via
   gtk_window/widget_destroy(). Calling gtk::main_quit() is not enough.

2. Since we lack a garbage collector, we need to fake it. We need to override
   del_ref handler on the object, which will make sure that our wrapper is
   destroyed only if the referent gobject also has refcount of 1, which we means
   that only we own it. Otherwise, we need to keep our wrapper from being
   destroyed and save a pointer to the wrapper in the gobject with notification
   turned on, so that when gobject is destroyed by Gtk+ our wrapper is destroyed
   as well.

[
  * todo
  - in progress
  + done
]