rm-logfiles

added const_type: sg -> typ option;
stamps now stored in REVERSE order;
now supports 'draft signatures' and incremental extension: is_draft,
add_classes (supports axclasses), add_defsort, add_types, add_tyabbrs,
add_tyabbrs_i, add_arities, add_consts, add_consts_i, add_syntax,
add_syntax_i, add_trfuns, add_trrules, add_name, make_draft;
added const_of_class, class_of_const (for axclasses);
changed the pure signature to support axclasses (added itself, TYPE);
various major 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