optionally do not write command line config to torrc
For Tor Browser/Tor Launcher, we have a use case where we want to pass ControlPort and SocksPort options on the command line (aka as program args) and be assured they will never be written to torrc, e.g., in response to a SAVECONF control port command.
See ticket:20906#comment:7 for some background. Also, in ticket:20906#comment:8 nickm said: I think that a "Don't write this to torrc" flag might be workable, but I also think it's maybe less easy to implement than you might think -- especially if it needs to work for things other than LineList options. If it's LineList only, it has a reasonable chance of being easy to implement.