Updated check_fail2ban to return performance data for all jails

Allows perf data from all jails to enable pnp4nagios to display a chart per jail when run with the command:
check_fail2ban -p -w 1 -c 5 -P /usr/bin/fail2ban-client

sample output:
CHECK FAIL2BAN ACTIVITY - CRITICAL - 9 detected jails with 5 current banned IP(s) | apache-noscript.currentBannedIP=0 sendmail.currentBannedIP=0 postfix.currentBannedIP=0 ssh-probe.currentBannedIP=3 ssh-ddos.currentBannedIP=0 apache-multiport.currentBannedIP=0 apache.currentBannedIP=0 ssh.currentBannedIP=2 apache-overflows.currentBannedIP=0
Updated check_fail2ban to return performance data for all jails and applied to specific jail code
Updated Thanks.
Updated Changelog
Merge pull request #500 from alasdairdc/master

ENH: Updated nagios check_fail2ban to return performance data for all jails