ROOTS

clarified options ML_source_trace and ML_exception_trace (NB: the latter needs to be a system option, since the context is sometimes not available, e.g. for 'theory' command);

src/Pure
src/FOL
src/HOL
src/ZF
src/CCL
src/CTT
src/Cube
src/FOLP
src/LCF
src/Sequents
src/Doc
src/Tools