Optimize is_subset and is_disjoint in cerl_sets
Optimize is_subset and is_disjoint in cerl_sets

The new implementation use maps iterators and are more
perfomant in banchmarks by roughly 10%. More importantly,
the iterators approach allow us to short-circuit and abort
early.

fold and filter have also been changed to use iterators.
We could simply delegate to the maps' functions, but
inlining the implementation allows us to skip a double
anonymous function dispatch.

RoadRunnr/otp,kvakvs/otp,bjorng/otp,mikpe/otp,kvakvs/otp,rlipscombe/otp,vinoski/otp,RoadRunnr/otp,getong/otp,dgud/otp,jj1bdx/otp,kvakvs/otp,erlang/otp,dgud/otp,electricimp/otp,electricimp/otp,jj1bdx/otp,g-andrade/otp,vladdu/otp,dgud/otp,uabboli/otp,RoadRunnr/otp,vladdu/otp,g-andrade/otp,ferd/otp,dgud/otp,erlang/otp,kvakvs/otp,isvilen/otp,dgud/otp,lrascao/otp,potatosalad/otp,ferd/otp,vinoski/otp,vinoski/otp,bjorng/otp,mikpe/otp,ferd/otp,isvilen/otp,getong/otp,uabboli/otp,bjorng/otp,RoadRunnr/otp,isvilen/otp,isvilen/otp,potatosalad/otp,vinoski/otp,jj1bdx/otp,erlang/otp,erlang/otp,dgud/otp,RoadRunnr/otp,erlang/otp,lrascao/otp,uabboli/otp,dgud/otp,dgud/otp,RoadRunnr/otp,g-andrade/otp,emacsmirror/erlang,vladdu/otp,bjorng/otp,jj1bdx/otp,isvilen/otp,getong/otp,rlipscombe/otp,isvilen/otp,rlipscombe/otp,jj1bdx/otp,electricimp/otp,lrascao/otp,getong/otp,isvilen/otp,emacsmirror/erlang,ferd/otp,getong/otp,vladdu/otp,bjorng/otp,potatosalad/otp,electricimp/otp,potatosalad/otp,rlipscombe/otp,jj1bdx/otp,mikpe/otp,electricimp/otp,kvakvs/otp,vladdu/otp,getong/otp,dumbbell/otp,dgud/otp,emacsmirror/erlang,electricimp/otp,vladdu/otp,RoadRunnr/otp,dumbbell/otp,dgud/otp,mikpe/otp,g-andrade/otp,ferd/otp,getong/otp,emacsmirror/erlang,g-andrade/otp,ferd/otp,ferd/otp,vladdu/otp,lrascao/otp,vinoski/otp,dumbbell/otp,rlipscombe/otp,erlang/otp,kvakvs/otp,vladdu/otp,g-andrade/otp,mikpe/otp,g-andrade/otp,ferd/otp,vinoski/otp,emacsmirror/erlang,mikpe/otp,electricimp/otp,mikpe/otp,kvakvs/otp,dumbbell/otp,bjorng/otp,g-andrade/otp,emacsmirror/erlang,g-andrade/otp,RoadRunnr/otp,kvakvs/otp,vinoski/otp,erlang/otp,lrascao/otp,ferd/otp,uabboli/otp,erlang/otp,potatosalad/otp,lrascao/otp,dumbbell/otp,uabboli/otp,dumbbell/otp,isvilen/otp,lrascao/otp,mikpe/otp,lrascao/otp,rlipscombe/otp,erlang/otp,bjorng/otp,erlang/otp,getong/otp,dumbbell/otp,uabboli/otp,electricimp/otp,isvilen/otp,dumbbell/otp,kvakvs/otp,rlipscombe/otp,bjorng/otp,uabboli/otp,emacsmirror/erlang,jj1bdx/otp,vinoski/otp,uabboli/otp,bjorng/otp,mikpe/otp,emacsmirror/erlang,potatosalad/otp,rlipscombe/otp,vinoski/otp,dumbbell/otp,potatosalad/otp,g-andrade/otp,rlipscombe/otp,jj1bdx/otp,potatosalad/otp,jj1bdx/otp,mikpe/otp,RoadRunnr/otp,electricimp/otp,bjorng/otp,emacsmirror/erlang,jj1bdx/otp,lrascao/otp,uabboli/otp,getong/otp,rlipscombe/otp,isvilen/otp,potatosalad/otp,getong/otp,dumbbell/otp,potatosalad/otp,emacsmirror/erlang,vladdu/otp,vinoski/otp