in-place increment for loop var in for -WARNING, this assumes variables are NEVER re-assigned, might break things
simplified NEXT for faster loops; almost all errors should be generated in FOR
further simplified NEXT (faster)
specialised inc_and_gt routine to replace otherise unused number_gt (faster FOR)
unpack for loop step, stop variables before loop
rewrite pop loop in loop_iterate
further unpack stop and step vars before loop (faster)
compactified number_inc_gt
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
Merge branch 'master' into fasterloop
don't drop FOR-NEXT stack on NEXT withonut FOR, allow to continue loop by RESUME or CONT
Merge branch 'master' into fasterloop