Feature: hide "mode" information

I would like to request that the mode changed..by message can be turned off. Maybe in a per channel configure?

In some channels where there is an auto-voice, you will get many useless "Mode +v by xxx" messages taking up all the screen in Conversations, and at least this mode is perfectly mirrored by changing affiliation to member (which biboumi does as well). Also I would argue many people do not care about modes, especially if they are not channel operators.

Thanks!