format is the same as toplevel pachi command (comma separated).
pachi-setoption adds specified option(s) to current set of engine options.
Options set through pachi-setoption persist across engine resets (clear_board etc).
You should get a gtp error if option is invalid.
Without argument pachi-getoption returns all engine options currently set (comma separated),
given option's value otherwise.
Adds 2 gtp commands to set/get engine options:
pachi-setoption <engine_options>
pachi-getoption [<option>]