Comment 5 for bug 323111

I've started working on this.

More precisely, I'm going to implement moving the un-versioned files into a top-level bzr-orphans directory and
emit a warning in this case.

0 is not appropriate as the problem may occur during a pull or a switch (the infamous .pyc problem).
2 can come later but I'd like bzrlib.ignores to be re-factored first so we can re-use it for .bzrjunk.

Note that I punt regarding the distinction between junk and precious by *not* deleting the file
but moving it out the way. It will be up to the user to regularly inspect/purge/delete the orphans directory.

There are various ways to name the files in the .bzr-orphans directory, I'll start with something simple
<file>~n~.