By THÉRÈSE MARGOLIS Hamburger sliders and mini pulled pork sandwiches, accompanied by parmesan fries and plenty of potent spirits, made for a lively evening of comradery and fervent debate at the re-opening of the American Legion Alan Seeger Post 2 in Mexico City’s Colonia Condesa on Friday, Oct. 22. The all-new Texas-style menu and ample mixology bill of fare, along