Add a new example app

Add a new example to the getting started part of the docs. The focus
of this example is on 'new stuff': GtkApplication, templates, settings,
gmenu, gaction, GtkStack, GtkHeaderBar, GtkSearchBar, GtkRevealer,
GtkListBox, GtkMenuButton, etc.

It is being developed in several steps. Each step is put in a separate
directory below examples/: application1, ..., application8. This is a
little repetitive, but lets us use the code of all examples in the
documentation.

examples/application4/Makefile.am

@@ -0,0 +1,31 @@
+AM_CPPFLAGS = \
+	-I$(top_srcdir)			\
+	-I$(top_srcdir)/gdk		\
+	-I$(top_builddir)/gdk		\
+	$(GTK_DEBUG_FLAGS)		\
+	$(GTK_DEP_CFLAGS)
+
+LDADD = \
+        $(top_builddir)/gtk/libgtk-3.la \
+        $(top_builddir)/gdk/libgdk-3.la \
+        $(GTK_DEP_LIBS)
+
+
+noinst_PROGRAMS = exampleapp
+
+exampleapp_SOURCES = \
+	main.c \
+	exampleapp.c exampleapp.h \
+	exampleappwin.c exampleappwin.h \
+	resources.c
+
+BUILT_SOURCES = resources.c
+
+resources.c: exampleapp.gresource.xml window.ui app-menu.ui
+	$(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) $(srcdir)/exampleapp.gresource.xml \
+		--target=$@ --sourcedir=$(srcdir) --generate-source
+
+EXTRA_DIST = \
+	window.ui \
+	app-menu.ui \
+	exampleapp.gresource.xml