Glib::ObjectBase: Replace extra_object_base_data map by instance data

* glib/glibmm/class.[cc|h]: Remove the clone_custom_type() overload without
an interface_class_vector_type argument.
* glib/glibmm/interface.cc:
* glib/glibmm/object.cc:
* glib/glibmm/objectbase.[cc|h]: Replace the std::map containing
ExtraObjectBaseData with instance data in ObjectBase. The map was just a way
of avoiding an ABI break, but now we can break ABI.
The new data is a std::unique_ptr<Class::interface_class_vector_type> rather
than a Class::interface_class_vector_type. It's a vector which is used only
during a short period during object construction, and only for custom objects.
With a pointer to the vector, it need not be created for the majority of
objects, and if it is created, it can be deleted when it's no longer needed.
* gio/src/application.ccg:
* glib/glibmm/main.cc: Add #include <mutex> that should have been there before,
but now became necessary, when it was removed from objectbase.h.

1 files changed, 1 insertions, 0 deletions

diff --git a/gio/src/application.ccg b/gio/src/application.ccg
index 785d050b..97f1c27d 100644
--- a/gio/src/application.ccg
+++ b/gio/src/application.ccg
@@ -21,6 +21,7 @@
 #include <giomm/init.h>
 #include <cstring> // std::memset()
 #include <map>
+#include <mutex>
 #include <vector>
 
 namespace // anonymous