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.

@yarikoptic :+1:  I understood
<blockquote>@kwirk recidive filter will need to be changed. I don't think recidive becomes completely obsolete...</blockquote> But I think, we should move the simply filter logic resp. watching to observer. I have checked system load by enabled recidive jail - it produce dual system overhead. With other words expressed: why we should read fail2ban.log to recognise events, written from fail2ban self, if observer module already knows all that?