{HOL,ZF}/indrule/ind_tac: now calls DEPTH_SOLVE_1 instead of REPEAT, to
solve the goal fully before proceeding
{HOL,ZF}/indrule/mutual_ind_tac: ensures that calls to "prem" cannot loop;
calls DEPTH_SOLVE_1 instead of REPEAT to solve the goal fully
{HOL,ZF}/intr_elim/intro_tacsf: now calls DEPTH_SOLVE_1 instead of REPEAT to
solve the goal fully