Vidalia should set __ReloadTorrcOnSIGHUP to 0 if it can't write its torrc file

The #4832 (moved) bug pointed out another bug: if Vidalia is used to control the system Tor on debian/ubuntu, and configuration changes are made, then Tor will get a daily hup that cancels all the config changes.

See #856 (moved) for how TorK solves this:

  __ReloadTorrcOnSIGHUP

    If this option is true (the default), we reload the torrc from disk
    every time we get a SIGHUP (from the controller or via a signal).
    Otherwise, we don't.  This option exists so that controllers can keep
    their options from getting overwritten when a user sends Tor a HUP for
    some other reason (for example, to rotate the logs).

    (Boolean.  Default: "1")

I wonder if TorK simply sets the config option when it first connects, or if it only sets it when it issues a saveconf, or if it only sets it if it issues a saveconf which fails.