BAGHDAD (Reuters) - Iraqi leaders are wrangling over who should succeed Saddam Hussein as president after they agreed on other key posts in the new government that will take power next month from the U.S. occupation authority. With the top post of prime minister filled and consensus on key ministries, Iraqi officials spoke on Sunday of sharp disagreement on the largely ceremonial choice of head of state between Adnan Pachachi, veteran scion of a pre-Saddam political dynasty, and Ghazi Yawar, a youthful engineer long based in Saudi Arabia. U.S. and U.N. officials may now be ready to propose a third...