All general ordinances of the city passed prior to the adoption of this code are hereby repealed, except such as are included in this code or are by necessary implication herein reserved from repeal (subject to the saving clauses contained in the following sections), and excluding the following ordinances which are not hereby repealed: tax levy ordinances; appropriation ordinances; contract ordinances and ordinances authorizing the execution of a contract or the issuance of warrants; ordinances relating to the transfer or acceptance of real estate by or from the city; ordinances authorizing a zone change; ordinances authorizing a bond issue; and all special ordinances. (2004 Code)