Terminal now maintains a sequence number that increments
for each Action that is applied to it.
Changes to lines are tagged with the current sequence number.
This makes it a bit easier to reason about when an individual
line has changed relative to some point in "time"; the consumer
of the terminal can sample the current sequence number and then
can later determine which lines have changed since that point
in time.
refs: https://github.com/wez/wezterm/issues/867
in the same vein as d657721163
this commit introduces more assertive signalling from the remote
mux when a pane is closed so that the client can update.
kindof a lot going on in this commit, unintentionally:
* Need the lua context set to be moved into the config crate
otherwise configs cannot be parsed by the server and we end
up with the default configs
* Make the server use smol for async io
* Drop the use of the daemonize crate, which I had forked anyway.
Just inline our own tighter daemonize module
* Improve daemon spawning synchronization, however, it still needs
work for windows to avoid blocking forever where we don't do
daemonizing.
