Symbol.source/OuterLex.source: more explicit do_recover argument;
scan: pass position;
removed obsolete prepare_command (now inlined in isar_syn.ML);
renamed prepare_command_failsafe to prepare_command, reports tokens;
load_thy: now based on ThyEdit operations, reports tokens and spans;
tuned;
By chapter:
chapters 1 and 2, maybe 3: Peter White
chapters 6, 7 and 8: David von Oheim
chapter 6, maybe 8: Gerwin Klein
chapters 3, maybe 4: Tanja Vos
chapters 1-3 at least: Stefano Bistarelli