1) All IRC clients support prefixes nowadays
2) People generally misunderstand the question and think this
disabled +q (channel owner) and +a (channel admin), when
in fact it does not. It only enables/disables the showing
of prefixes, and it changes some of the rules eg requiring
+qo / +ao for actions that normally only require +q / +a.
3) We now have the modularized +q and +a, so you can actually
disable channel owner and channel admin, which is what most
users want(ed) that previously disabled PREFIX_AQ.
For all users (95%+) that enable PREFIX_AQ there is no effective
change. For the other 5% it is likely only for the better.
I don't think there were more than a handful of people who disabled
this, and it clutters the source badly (not to mention that this
should not be a compile time option at all).
setting the default class::sendq that pretty much everyone overrides
in class (isn't this even required? ;D).
Rename to DEFAULT_SENDQ since we have DEFAULT_RECVQ too.
