Serendipity Gallery in the Delmar Loop (6161 Delmar Blvd.; 314-449-6400) announced its impending closure on Facebook this past Wednesday. The lights go out for the final time at 9 p.m. on Saturday, December 30.The four-year old gallery was founded by sisters-in-law Rose Hagan and Lisa Ann Houdyshell as a place to show work in all media by local and national artists.…