in U.S. Pat. No. 4,101,513) and organic acids and their salts or other derivatives such as the highly fluorinated sulfonic and sulfonylic acids as described in U.S. Pat. No. 4,049,861; and ionic salts of organometallic complexes as disclosed in European Patent Office laid-open documents EP-A-O No. 094 914 and EP-A-O No. 094 915.