Expose arbitrary FUSE mount options

[jmmv]

I'm playing with bb-clientd and observing that performance doesn't seem great in some cases. From past experience with similar pprof profiles, I wanted to try passing some additional mount options to FUSE to check if they make any difference, but this is currently not possible.

Right now, the configuration offers a way to set AllowOther and DirectMount but nothing else. What do you think about extending this to support other options exposed by FUSE according to fuse.MountOptions? The proto would expose the individual options, or it would simply allow passing a collection of strings via the Options field, as these are passed verbatim to the FUSE mount.

[EdSchouten]

I’m fine with that, but please limit yourself to the features you actually need. There is no need to add support for all of these options.

My preference is to pass through options verbatim if possible. Imposing a certain workflow only adds more code, while reducing flexibility.