recognize bus errors as crash

consider removing chained facts last, so that they're more likely to be kept

clarified format of etc/options: only declarations, not re-definitions;

check_errors for cumulative session content;

even more defensive path expansion (see also 8d381fdef898);

support for 'typ' with explicit sort constraint;

added jedit option -d;

always retain doc-src (as regular component);

merged

Calling isabelle with proper (relative) path, no longer relying on $PATH.

fewer workarounds for MacOS to increase chances that COMMAND ("META") key works with Java 1.7 from Oracle;

updated to jedit-4.5.2 (still unchanged);

restored ISABELLE_OUTPUT etc -- still relevant at least for mira.py itself

tuned;

fixed mira.py (cf. fd50596bf78b)

more direct embedding of abstract thm values into the ML environment -- avoidance of repeated ML_Thms.the_thm(s) considerably reduces compilation time for Poly/ML 5.4.x;

more static antiquotations;

always show some timing information, to reduce the need for explicit -v;

some information for central Isabelle repository configuration;

reduced settings patching

removed obsolete configuration AFP_images

faster compilation of ML with antiquotations: static ML_context is bound once in auxiliary structure Isabelle;

simplified symbol matching;

further clarification of malformed symbols;

more liberal scanning of potentially malformed symbols;

vacuous execution after first malformed command;

clarified Command.range vs. Command.proper_range according to Scala version, which is potentially relevant for command status markup;

tuned markup;

tuned message;

clarified "bad" markup: proper body text, invent missing serial on Scala side (counting backwards);