BF: aInfo could be modified by actions, causing unexpected behaviour

A separate copy of aInfo is passed to each action
TST: Test for actions modifying (un)ban aInfo
TST: actions modifying aInfo test more robust
Merge branch 'ainfo-copy' of https://github.com/kwirk/fail2ban

* 'ainfo-copy' of https://github.com/kwirk/fail2ban:
  TST: actions modifying aInfo test more robust
  TST: Test for actions modifying (un)ban aInfo
  BF: aInfo could be modified by actions, causing unexpected behaviour
BF: reincarnated import of logging (used to obtain level constants)