[rfc] Windows symlink support

[Jamie Wilkinson]

This one time, at band camp, John Arbash Meinel wrote:
>I would like to add a small point here. One very useful use case for
>versioning /etc is not for backups, but actually for system
>administration over multiple machines.

I had a rant brewing earlier, but decided against posting it because it was
less about bzr support for symlinks and more about best practices.  (I
realised I wasn't opposed to bzr supporting symlinks if people really think
they want it.)

>Say you version /etc/hosts.allow, they you can push around that change
>so that all the machines now have a new entry in hosts.allow.
>
>Or you modify the configuration for httpd, and you have multiple
>machines running for distributed workload.

I don't see how you're using symlinks in either case, but for the sake of
argument:

Both these use cases are more easily solved using management agents like
puppet or cfengine; pushing symlinks out from your RCS is a terrible way to
handle this.  Usually one requires a tool run after the RCS push to modify
the final layout.  In such a case I've found it best to let this tool do the
linking itself, and leave the symlinks out of revision control.

>Some people version $HOME, which I have started playing around with.
>Mostly because I have 10 different machines I work on, at various sites
>(home, work, laptop, school, etc), where doing an NFS mounted home
>directory is not possible (kind of hard to do on an airplane), but it
>also sucks to try and keep my ~/.vimrc .vim/* in sync.

Again, not symlinks :)