* configure.in: Added python/pygtk checks.

* src/Makefile.am: added glade-binding.[ch] and BUILD_PYTHON rules

* src/glade-app.c:
  o added glade_scripts_dir and glade_bindings_dir globals
  o loading / unloading bindings.

* src/glade-binding.[ch]: GladeBinding support this is the glue code
  between glade core and bindings modules.

* src/glade-catalog.c: support for loading catalogs supported by
  bindings, added language member to GladeCatalog.

* src/glade-marshallers.list: added new marshallers BOOLEAN:STRING and
  BOOLEAN:OBJECT,STRING

* src/glade-paths.sh.in: added GLADE_BINDINGSDIR and GLADE_SCRIPTSDIR.

* src/glade-popup.c: added support for GWAAction
  (shows context actions as menu items)

* src/glade-project-window.c: added window which a console for each
  GladeBinding that provide a console.

* glade-python-gwa.c: GladeWidgetAdaptor python wrapper.

* glade-python-gwa.[defs override]: files used by pygtk-codegen-2.0
  to create glade-python-gwa.c

* glade-python.c: GladeBinding plugin for python language.

* src/glade-widget-adaptor.[ch]:
  o added GWAAction support.
  o added "action-activated" signal
  o added glade_create_reason_get_type() so the enum can be exposed in
    bindings as a GEnum.
  o added "adaptor" property to glade-widget-class this way non C catalog
    plugins can define the GladeWidgetAdaptor derived class.
    <glade-widget-class name="Custom" adaptor="CustomAdaptor"/>
  o setup binding scripts as actions.
  o added glade_widget_adaptor_emit_action_activated()
    (used in glade-popup.c)

* src/glade-widget.[ch]: added "action-activated" signal.

* src/glade.h: added GLADE_TAG_LANGUAGE, GLADE_TAG_ACTION_GROUP,
  GLADE_TAG_ACTION, GLADE_TAG_STOCK, glade_scripts_dir and
  glade_bindings_dir.