tahoe --node-directory=foo start/stop seems to ignore foo.

[nejucomo]

For example:

$ ps aux | grep tahoe
tahoe     5786  0.0  7.4 187260 37356 ?        Sl   17:45   0:00 /usr/bin/python /usr/bin/tahoe start
n         6027  0.0  0.1   9388   928 pts/1    S+   18:01   0:00 grep tahoe
$ sudo -u tahoe tahoe --node-directory=/home/tahoe/.tahoe stop
STOPPING '/home/n/.tahoe'
'/home/n/.tahoe' does not look like a running node directory (no twistd.pid)

[warner]

Tahoe's command+subcommand parser takes arguments in two places: tahoe --ARG1 SUBCOMMAND --ARG2. It looks like we're ignoring --node-directory when it appears in ARG1, only paying attention to it when it appears in ARG2.

This is another aspect of #166, so I'll close this as a dup and update the other ticket.