Linking of message accounts is now significantly less likely to produce
false-positives.
Previously, any hostmasks with matching nick!*@* would be strongly linked
together. This led to falsely-linking accounts, either inadvertently or
intentionally.
For example, Bob might also be known as Bob_ and Bobby,
but primarily uses Bob as his main nick. Somebody else might join with
Bobby and end up being linked to Bob. Now both Bob and the new Bobby are
linked together as the same person, but likely with different *!user@host.
Now if the new Bobby ever gets banned, then Bob will also end up being
banned for evading Bobby's ban.
This was a sore spot in the previous linking implementation.
This new implementation has several adjustments to more intelligently link
accounts only when they're proven beyond a reasonable doubt to be the same
person (e.g. by matching nickserv accounts, etc).
Consequently, rather than aggressively linking accounts and catching more
ban-evaders at the risk of potentially falsely-linking accounts and falsely
detecting innocent people as ban-evaders, this new implementation will instead
link accounts more reliably at the risk of potential ban-evaders not yet being
linked together and thus being able to evade a ban.
This is a more preferable and reasonable risk. Active channel ops should be
able to catch any obnoxious ban-evaders that slip through this net.
Extremely minor rearrangement of interpreter logic so that `!commands` are
parsed before `command, botnick`. Totally not a bug at all. Pay no attention.