* dbus/dbus-marshal.c:
	(_dbus_marshal_set_string):
	Take a length argument so we can marshal the correct string
	length.

	(_dbus_marshal_dict), (_dbus_demarshal_dict),
	(_dbus_marshal_get_arg_end_pos), (_dbus_marshal_validate_arg),
	(_dbus_marshal_test):
	* dbus/dbus-marshal.h:
	Add support for marshalling and demarshalling dicts.

	* dbus/dbus-message-builder.c: (_dbus_message_data_load):
	Add support for TYPE DICT.

	* dbus/dbus-message.c: (set_string_field):
	Adjust header padding.

	(dbus_message_append_args_valist), (dbus_message_append_dict),
	(dbus_message_get_args_valist), (dbus_message_iter_get_arg_type),
	(dbus_message_iter_get_dict), (_dbus_message_loader_return_buffer),
	(check_message_handling), (check_have_valid_message):
	* dbus/dbus-message.h:
	Add functions for setting and getting dicts.

	* dbus/dbus-protocol.h:
	Add DBUS_TYPE_DICT.

	* dbus/dbus.h:
	Add dbus-dict.h

	* doc/dbus-specification.sgml:
	Add information about how dicts are marshalled.

	* test/data/invalid-messages/dict-with-nil-value.message:
	* test/data/invalid-messages/too-short-dict.message:
	* test/data/valid-messages/dict-simple.message:
	* test/data/valid-messages/dict.message:
	Add sample messages containing dicts.