ENH: Add fail2ban persistent data storage
TST: Fix test for fail2ban.conf with new database options
BF: Fix dbpurgeage default value, and change default dbfile extension
BF: Improve handling of clearing old jails in database
ENH: Remove thread locks from Fail2BanDb
ENH: Database now optional, by setting dbfile to "None"
ENH: Add getBansMerged method to Fail2BanDb

Creates a single ticket for an IP, made up of all previous bans
MRG: branch 'kwirk/database' into 0.9 - gh-480

Conflicts:
	fail2ban/tests/utils.py
        - Another test suite added in separate commit e09b700