Pyridonecarboxylic Acids as Antibacterial Agents. Part 9. Synthesis and Structure-Activity Relationship of 3-Substituted 10-(1- Aminocyclopropyl)-9-fluoro-7-oxo-2,3-dihydro-7H-pyrido(1,2,3-de)-1,4- benzoxazine-6-carboxylic Acids and T