For basic uspot setups, this commit implements a 'generate' verb to
uspot /usr/bin/captive that takes a config uspot section name, and
parses the following extra options to generate the relevant spotfilter
config:
option generate_spotfilter (bool) # if unset/false, generate is a NOP
option interface 'name' # config/network interface name to redirect to
option client_autoremove (bool) # if set/true, sets client_autoremove
list wl_hosts '*.example.com' # optional list of whitelist hostnames
list wl_addrs '1.2.3.4' # optional list of whitelist IPs
"captive generate" is called in spotfilter.init to optionally (depending
on 'generate_spotfilter') create the required spotfilter-XXX.json before
starting spotfilter.
Signed-off-by: Thibaut VARÈNE <hacks@slashdirt.org>
