provide node header via Scala layer;
clarified node edit Clear: retain header information;
run_command: node info via document model, error handling within transaction;
node names without ".thy" suffix, to coincide with traditional theory loader treatment;
(* Title: HOL/Quotient_Examples/ROOT.ML
Author: Cezary Kaliszyk and Christian Urban
Testing the quotient package.
*)
use_thys ["DList", "FSet", "Quotient_Int", "Quotient_Message", "Cset", "List_Cset"];