small improvements - physics unchanged

[cbernet]

• improved ZH tree, should only affect myself.
• looper:
  • some cleanup in the code.
  • the time report is now always done
  • the looper now prints an analyzer flow to show the probability to pass each analyzer in the sequence
• pythia_batch : now submitting a job every 2 s (was 5 s).

[fcc-bot]

All tests succeeded.

[fcc-bot]

Build or tests failed.

[cbernet]

retest this please

[fcc-bot]

All tests succeeded.