Update config/jail.conf

Update to use the new sogo-auth filter
Create sogo-auth.conf

Regexp works with SOGo 2.0.5 or newer, following new feature implemented here: http://www.sogo.nu/bugs/view.php?id=2229
Update config/filter.d/sogo-auth.conf

Comment line in the top altered to fit file name. My local file was named differently...
Update sogo-auth.conf

included hint by user  yarikoptic
An example of failed logins against sogo
Merge remote-tracking branch 'pr/117/head'  -- SOGo filters

* pr/117/head:
  An example of failed logins against sogo
  Update sogo-auth.conf
  Update config/filter.d/sogo-auth.conf
  Create sogo-auth.conf
  Update config/jail.conf
ENH: Slight tune ups for fresh SOGo filter + comment into the sample log file