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.