With IRCv3.2 echo-message, each successfully sent message would
move us to the front of the list used for chanuser autocomplete.
Such behaviour seems useless.
Also abandon the idea of bumping on other kinds of messages.
Replaces the inaccurate Rec. 709 luma we used to use before.
This is the first feature here that requires libm, which doesn't
seem to be a particularly great sacrifice.
Moreover, I've rectified that the input isn't linear in sRGB,
and then was even normalized wrong for the luma formula.
It didn't make sense to have these unimplemented,
though perhaps += shouldn't enforce a set.
Sadly, autocomplete is fairly difficult for -= of multiple items.
It was super annoying to just slightly modify strings and
string arrays, now you can have existing values filled in.
complete_word() looks a bit cleaner now as well.
Now that the input to the backlog helper is wrapped the same way
as what we display. There's a slight issue always triggered by
fancy-prompt.lua where a multiline prompt/command line makes less(1)
go too high up but it's nothing too important.
Ensure the error stack is cleared after errors are processed.
Also handle NULL returns safely.
Makes the debug mode spew more data, though almost none of
the contexts is in reaction to network peer data.
The worst offenders are actually OpenSSL and Lua, this is
mostly about a preventable surprise.
This is more correct because we mix escape sequences for
attributes with text, however in practice no one will use
shit-jizz with degesch.
It is also a clean-up: "struct line_char" has been almost
halved in size. We used to use it as a cache and now we
recompute the multibyte sequence.
Of course, it'd be best to get rid of the linked list but
it would take a very long time to rewrite the algorithm.
Plus, it's not certain that it could be improved by much.
The change in "struct line_char_attrs" is merely cosmetical.
I've had this happen to me on Russian channels and it's highly
annoying because you lose the entire message. On the contrary,
this at worst screws up the last few characters of it.
Closes#2
