This is useful for cases where some programs expect to be able to use
the tmux passthrough escape sequences by using the tmux passthrough
sequence.
One such example is `osc52` script I packaged.
However I like the idea of tmux filtering all escape sequences by
default, so it's not enabled by default.
Turns out it is more trouble than it is worth trying to make this work:
with the secure socket problem etc...
The first start up is fast enough for me in the end.
This reverts commit cc21d84808.
The service definition is pretty awful, but it deals with the secure
socket correctly...
This avoids having a small lapse when starting the very first shell of a
session, which must first launch the server.
Bruno BELANYI