Add list of ignored players. Adds ESS-4456

Now when you type /ignore with no arguments it prints a list of players
you have ignored. If you are not ignoring any players, it tells you that
and tells you how to ignore someone.

Picture of default output http://o.snw.io/ZD6x
Merge pull request #561 from drtshock/2.x

Add list of ignored players. Adds ESS-4456