fixes + optimizations
- fix get num waiting per cluster
- optimize get num waiting per cluster
- don't check num waiting if no more combinations
- more logs
time iteration of schedule loop
update gitignore
schedule loop optim: don't ask the frontend for num of waiting jobs,
maintain it myself
change delay between schedules from 20 to 10
change max workers from 10 to 20
change default num xp replicas from 1 to 5
less verbose logs