[ error / not_in_the_roster / resquested / message ] icons should be unified and no more depends of transports iconsets
The fact of these icons depending of transport iconsets is very confusing, each transport iconset can have a different icon for each of these events, very bad for eyes and ergonomic sense. So the way seems to be ejecting these icons from transports iconsets, and do things to let each of these events reaching the icon it needs in a unique place.