Kick/ban log and bans in database

[MrBondt]

I finished the import. I've also made a couple of changes to the table structure, which I've outlined in my edited post above.

About the import:

• I didn't bother with looking up IDs for subject names or user names in order to get the data in there sooner.
  
• IP addresses are missing from entries of date 2009-11-29 20:52:09 and older since we started storing them after that date.
  
• Items of date 2009-02-24 00:50:08 and older did not include the year number. These have been derived by just counting down with the month number.