Support rxvt-style keys again, but this time: support all the variations, put
them in as raw escape sequences rather than fiddling with the values from
terminfo, put them /after/ the terminfo values so the latter take precedence.
Rewrite a confusing loop when freeing the arg array on exit and move the check
for argv being NULL, prompted by parfait via deraadt.
Also fix some definite brokenness when assigning multiple environment variables
in arguments (such as "X=1 Y=2").
Add an explicit zero-length check for UTF-8 input data, prompted by a report
from parfait via deraadt.
While here, add a statement to set the width when filling with _s if not enough
space (width should never be high enough at the moment anyway), and wrap some
long lines.
There is no real standard for modifier plus function keys. Previously, tmux
output some from rxvt but in other ways did the same as xterm or other
terminals, but this is a bit inconsistent.
xterm's method is fairly sensible and we already support it (xterm-keys), so
enable it by default instead.
Clear to the end of the screen from the right starting point when drawing
line-by-line (in panes or if ed not supported). Fixes problem spotted by Frank
Terbeck.
Switch the tty key tree over to an (unbalanced) ternary tree which allows
partial matches to be done (they wait for further data or a timer to expire,
like a naked escape).
Mouse and xterm-style keys still expect to be atomic.
key_string_lookup_key uses a static buffer, so copy its output into the working
buffer before calling the command print function which can also use it (eg
send-keys).
Switch tty key input over to happen on a read event. This is a bit more
complicated because of escape input, but in that case instead of processing a
key immediately, schedule a timer and reprocess the bufer when it expires.
This currently assumes that keys will be atomic (ie that if eg F1 is pressed
the entire sequence is present in the buffer). This is usually but not always
true, a change in the tree format so it can differentiate potential (partial)
key sequences will happens soon and will allow this to be fixed.
Convert the window pane (pty master side) fd over to use a bufferevent.
The evbuffer API is very similar to the existing tmux buffer API so this was
remarkably painless. Not many possible ways to do it, I suppose.
Initial changes to move tmux to libevent.
This moves the client-side loops are pretty much fully over to event-based only
(tmux.c and client.c) but server-side (server.c and friends) treats libevent as
a sort of clever poll, waking up after every event to run various things.
Moving the server stuff over to bufferevents and timers and so on will come
later.
