save image for inner nodes only; misc tuning and simplification;

some actual build function on ML side; further imitation of "usedir" shell script;

tuned -- no dependency on exit function;

more ML_System operations;

restricting Quickcheck_Examples' root file to one basic theory to see if the system error on isatest still occurs

handling partiality in the case where the equality optimisation is applied

merged

updated File.find_files;