The neighborhoods with the most character are often historic and central. For this reason, it was probably inevitable that the Historic Rainey Street neighborhood in the heart of downtown would become a very cool district of restaurant and bars. First came Lustre Pearl and Clive. Then, the G' Raj Mahal Cafe. Now, three more houses are entering the process to become restaurants or bars. Since the entire district is registered as a National Historic District, all such requests must pass through Austin's Landmark Commission.The Rainey Street District is located between the convention center and the lake just West . . .