Make optional members in JSDoc comments more consistent with Firefox's
codebase.

Bug 10439: Ask the the SOCKS port to the tor process.

Allow specifying a negative port as TOR_SOCKS_PORT to let the tor
process choose one for us.

This does not play too well with DisableNetwork, which we use to start
and stop the bootstrap, so we have to query the port every time we
change this setting.

Also, currently we use Firefox's preferences for SOCKS port.
This prevents us from keeping a negative number saved in them.
See also #42062.

Bug 42714: Allow to optionally use a TCP listener on Android.

Bug 42714: Allow to optionally use a TCP listener on Android.