class Session models full session, with or without prover process (cf. heaps, browser_info); replaced Prover by Session, with a singleton instance in Isabelle plugin (shared by all active buffers); misc cleanup of Session vs. Plugin instance; eliminated Prover_Setup -- maintain mapping of JEditBuffer <-> Theory_View directly; misc tuning and simplification;

tuned;

basic setup for HTML_Panel event handling;

install_fonts;