Fixed Bug #679589 "Use Action Appearance not supported for GTK 2.12 but added to widgets in Glade 3.8.2"
Made sure use-action-appearance is not saved if there is no action defined

Added glade_displayable_value_is_disabled/set_disabled() functions to disable GdkModifierType reserved values

Added build/mingw-w64 directory with script tp cross compile and create windows installer using nsis

Removed old undefined symbols to fix build error on windows
	glade_app_get_plugins_dir()
	glade_catalog_supports_libglade()
	glade_catalog_supports_gtkbuilder()
	glade_signal_editor_construct_signals_list()

Fixes bug #675977 "Don't hard-code library search paths"

gtk_builder_add_from_resource()

Set save=false to every GtkActivatable properties since they are always saved in glade_gtk_widget_write_widget()

Fixes bug 588981 "Catalog support in GUI preferences instead of using environment var"

Made glade_app_get_config() returna  static pointer so that it can be used before creating a GladeApp