Feature request: Exclude option for some commands

Hi folks,

I would find an --exclude option useful in a number of situations. In my case, I have several directories in my top level, but one of these is intended to be committed hourly by a cron script, while the others are committed manually. I have no way to ignore the automatically committed directory (as opposed to specifying the manual directories) in a top level commit without resorting to the shell.

.bzrignore can't be used for this purpose because versioned files aren't ignored.

I'm sure an option of this nature would be useful in other commands as well.

AIUI, Mercurial has a similar feature. Thanks for your time!