comment out part of has_emp_no_fail

and fix remaining evaluate' inductions in ml_translatorScript.sml
rework DeclAssum and DeclAssumC to start with the init_envC

because we need cenv_bind_div_eq to hold in order to move from DeclAssum
to DeclAssumC.
fix ml_optimiseScript.sml

leaving Handle expressions untouched by the optimiser (as previously)
fix ml_translatorLib.sml for changes to exceptions

not sure this is correct, but it seems to work