eliminated strange mutable var commands; removed_commands: refer to old commands; misc tuning;

updated header;

eliminated obsolete isabelle.proofdocument.Token;

do not override Command.hashCode -- which was inconsistent with eq anyway; unparsed: no id, commands observe pointer equality; actually invoke edit_commands; more correct doc_edits; tuned;

renamed Command.content to source; reorganization of document parsing, using command spans etc. -- initial setup;

further tuning of command_start;

refrain from poking blink rate -- might get stuck in invisible state;

eliminated Command.stop, which tends to case duplicate traversal of commands;

iterators for ranges of commands/starts -- avoid extra array per document; try/finally for saved_color; misc tuning;

tuned document changes;