As we noted here a month or so ago, the Henry Miller's Theater in New York is being renamed the Stephen Sondheim Theater. Apparently, this was arranged without the knowledge or permission of Mr. Sondheim. He found out about it on his 80th birthday, March 22, when he appeared onstage for a celebration at the new Broadway production, Sondheim on Sondheim. Here are the curtain calls from that evening, following by everyone singing Mr. Sondheim a song he probably wishes he'd written, followed by the announcement. He seems genuinely overwhelmed at the news. The two men breaking the news are his frequent collaborators, James Lapine and John Weidman…