Changes to 1.0.21 * Add vibrating drumhead modes example, heat equation with explicit FDM, improve the Laplace FDM example * Fix output of chopped floating point numbers, especially chopped imaginary parts * Fix output of results as floats in pretty print * Fix SurfacePlotVariableNames to redraw when changing variable names * Translation updates (Мирослав Николић, Rafael Fontenelle, Wolfgang Stöggl, Samir Ribic, Piotr Drąg, Miguel Rodríguez Núñez, Marek Černocký, Dimitris Spingos, Pedro Albuquerque, et moi) * During making of these changes the author (Jiri) was partially supported by NSF grant DMS 1362337 and the Oklahoma State University