Fix issues discussed in PR #5
Fix issues discussed in PR #5

- Ignore function should now work as expected
- Base user activity solely on their 'message activity'
    - This should solve the join/part spam
- Initialize ignore_chans array only once on a script load
- Add an option to ignore filtering of a QUIT signal
    - Behavior is unfortunately same as with NICK signal, so the signal
      is not filtered globally for all channels/servers

lifeforms/irssi-smartfilter