added pretty_sg;
added infer_types;
removed subclasses arg of add_classes;
removed old 'extend' and related stuff;
various minor internal changes;
#! /bin/sh
#rm-logfiles: remove useless files from subdirectories
rm log */make*.log */make*.log.gz
rm */test
rm */.*.thy.ML
rm */ex/.*.thy.ML
rm HOL/Subst/.*.thy.ML