wayland: Fix gdk_keymap_translate_keyboard_state

I was confusing indices and masks here, which made the modifier
translation go wrong. With this commit, accelerators work.
csd: Implement hide-titlebar-when-maximized
wayland: Implement gdk_keymap_get_modifier_state
GtkScale: Properly chain up in GtkBuildableIface->custom_finished()

This was causing <style> markup to be ignored when specified
on GtkScale types.
Deprecate gtk_widget_push_composite_child & friends

Deprecate gtk_widget_push_composite_child, gtk_widget_pop_composite_child,
gtk_widget_set_composite_name, gtk_widget_get_composite_name.

This API is just bloat and was never useful, this patch deprecates
it and removes all internal calls to the composite child APIs
Work around access to global resources without calling gtk_init()

Some utilities such as GIR and gtk-doc, initialize class vtables without
initializing GTK+, with composite templates accessing resources this
causes a hand full of unneeded warnings.

The workaround for now is the use a private function _gtk_ensure_resources()
which is both called while initializing GTK+, and at the beginning of
gtk_widget_class_set_template_from_resource() (the private function
ensures that the resource will only ever be registered GOnce).
GtkBuilder: Added api to allow private signal callbacks

In preperation for composite objects, for better encapsulation
the following APIs are added to allow handling of signals declared
in the XML with callbacks declared statically.

  o gtk_builder_add_callback_symbol[s]()

    Adds a symbol to the internal symbol hash

  o gtk_builder_lookup_symbol()

    Looks up a symbol, exposed in case added symbols are used
    in conjunction with gtk_builder_connect_signals_full()

The default implementation of gtk_builder_connect_signals() now
does not have a strong requirement on GModule (or a strong requirement
on symbols being declared in the global namespace). Instead GModule
is used as a fallback in the case that symbols are not declared
explicitly.
GtkBuilder: Add private _gtk_builder_extend_with_template()

This adds the definition of the <template> tag with some documentation
on the variant of the format.

_gtk_builder_extend_with_template() is to be used while GtkContainer
builds from composite templates. A couple of error codes are also added
to handle a few new possible failure cases.

DTD Files gtkbuilder.rnc and gtkbuilder.rng have been updated to include
the new <template> tag and it's attributes.
GtkBuilder: Allow G_PARAM_CONSTRUCT properties to be set on internal children.

This patch allows properties of type G_PARAM_CONSTRUCT to be set
on internal children or explicitly constructed objects (built
with <constructor>) while previously, G_PARAM_CONSTRUCT properties
being set on already constructed objects would result in an misinformed
warning that "construct-only properties cannot be set".

G_PARAM_CONSTRUCT_ONLY properties are still refused as parameters
to already constructed children.
Add Composite Child machinery and APIs to GtkWidget

This commit implements the needed machinery for GtkWidget
to build it's composite content from GtkBuilder XML and
adds the following API:

  o gtk_widget_init_template()

    An api to be called in instance initializers of any
    GtkWidget subclass that uses template XML to build it's components.

  o gtk_widget_class_set_template()

    API to associate GtkBuilder XML to a given GtkWidget subclass

  o gtk_widget_class_automate_child()

    API to declare an object built by GtkBuilder to be associated
    with an instance structure offset and automatically set.

 o gtk_widget_get_automated_child()

   API for bindings to fetch a child declared to be automated by
   gtk_widget_class_automate_child(), for the case where bindings
   do not generate GObjects under the hood and cannot use structure
   offsets to resolve composite object pointers.

 o gtk_widget_class_declare_callback[s]()

   Declare static functions to be used in signal callbacks from
   a given class's template XML

 o gtk_widget_class_set_connect_func()

   API for bindings to override the signal connection machinery
   for a given GtkWidget derived class.
Added directory with Glade catalog

This catalog can be used to work with GTK+'s private widget types,
this patch exposes a private function gtk_glade_catalog_init() which
Glade will use for the sole purpose of initializing some private widget
types in GTK+ that are referenced from various GTK+ composite widget
xml files.
GtkDialog: Define children with a GtkBuilder template

As the first composite widget in GTK+, this patch also
adds some Makefile mechanics to list the ui files as
dependencies of the global GTK+ resources, and adds the
initial test case where composite classes should be tested.
GtkMessageDialog: Define children with a GtkBuilder template
GtkInfoBar: Define children with a GtkBuilder template
GtkAboutDialog: Define children with a GtkBuilder template
GtkLockButton: Define children with a GtkBuilder template
GtkAssistant: Define children with a GtkBuilder template
GtkScaleButton: Define children with a GtkBuilder template
GtkStatusbar: Define children with a GtkBuilder template
GtkAppChooserWidget: Define children with a GtkBuilder template