Friday night’s 10-year anniversary party for Busboys & Poets brought hundreds of well-wishers to the restaurant and bookstore chain’s Brookland location in Northeast Washington.It was an evening of great music, delicious food and old-style rabble-rousing from such legendary activists as Alice Walker and Angela Davis. For founder and owner Andy Shallal, it was joyous confirmation of a dream that hardly seemed possible a decade ago, when bookstores were in rapid decline.