* dbus/dbus-internals.h:
	Fix build without tests.

	* dbus/dbus-list.c: (alloc_link):
	Fix a segfault when a malloc fails.

	* dbus/dbus-memory.c: (initialize_malloc_debug), (dbus_malloc),
	(dbus_malloc0), (dbus_realloc):
	Add support for malloc debugging.