Ban time incr

New feature "automatically exponential increasing ban time".
WARNING: by first start the server upgrades sqlite database (table "bans" will recreated with another schema);
Option "bantime.increment" in jail.conf allows to use database for searching of previously banned ip's to increase a default ban time using special formula, by default each next ban increase banTime * 1, 2, 4, 8, 16, 32...
see "jail.conf" for some other options of "bantime.___";
additional we can configure a little randomization of ban time, to prevent "clever" botnets calculate exact time IP can be unbanned.

may be for that all the additional information should go into separate log msgs at the debug level?