Also fix up some return values and stuff to use bool (or void if
nothing). I just did it whilst I was here.
According to jilles, the return value used to signify whether or not the
client had exited. This was error-prone and was fixed a long, long time
ago, but the return value was left int for historical reasons.
Since the return type is not used (and has no clear use case anyway),
it's safe to just get rid of it.
A KLINE command without the ON clause now sets a propagated
("global") ban. KLINE commands with the ON clause work as
before.
Propagated klines can only be removed with an UNKLINE command
without the ON clause, and this removes them everywhere.
In fact, they remain in a deactivated state until the latest
expiry ever used for the mask has passed.
Propagated klines are part of the netburst using a new BAN
message and capab. If such a burst has an effect, both the
server name and the original oper are shown in the server
notice.
No checks whatsoever are done on bursted klines at this time.
The system should be extended to XLINE and RESV later.
There is currently no way to list propagated klines,
but TESTLINE works normally.
