merged

less intermediate data structures

Isabelle_Process: more robust rendezvous, even without proper blocking on open (Cygwin);

simplified Isabelle_System.mk_fifo: inlined script, append PPID and PID uniformly;

refined Isabelle_Process startup: emit \002 before rendezvous on fifos, more robust treatment of startup failure with timeout, do not quit() after main loop; tuned;

back to default fold painter -- Circle looks slightly odd in conjunction with bracket matching;

message_actor: more robust treatment of EOF;

simplified Isabelle_Process message kinds; misc tuning and simplification;

recovered basic session stop/restart;

simplified fifo handling -- rm_fifo always succeeds without ever blocking; tuned;

raw_execute: let IOException pass-through unhindered (again);

mkfifo: some workaround to ensure reasonably unique id, even on Cygwin where $PPID might fall back on odd default;

Isabelle_System.mk_fifo: more robust enumeration of unique names, based on persisting JVM pid (parent of shell process);

slightly more robust Isabelle_Process startup -- NB: openening fifo streams synchronizes with other end, which may fail to reach that point;

tuned;

separate Isabelle.logic_selector;

non-editable text area;

basic setup for prover session panel;

ML_Syntax.print_char: more readable output of some well-known ASCII controls -- this is relevant for ML toplevel pp;

discontinued Output.debug, which belongs to early PGIP experiments (b6788dbd2ef9) and causes just too many problems (like spamming the message channel if it is used by more than one module);

Isabelle_Markup.overview_color: indicate error / warning messages;

some specific message classification;

Syntax.read_asts error: report token ranges within message -- no side-effect here;

Isabelle_Process: status/report do not require serial numbers;

simplified some internal flags using Config.T instead of full-blown Proof_Data;

tuned signature of (Context_)Position.report variants;

merged

merged