This is an application of the xdg activation protocol that will allow
compositors to associate new foot toplevels with the command that
launched them.
footclient receives an activation token from the launcher which the
compositor can use to track application startup. It passes the token
to the foot server, which then activates the new window with the token
to complete the startup sequence.
Send a generic “overrides” list to the server, containing options in
text, on the format “section.key=value”.
This reduces the size of the base client/server protocol packet, as
well as opens up for a generic -o,--override command line option (not
yet implemented).
Instead of writing (and logging errors for) every parameter, one at a
time, send all fixed size data in a single struct, followed by all the
variable length data.
