FUSE permission handling has changed, --no-default-permissions is undocumented

[longwave]

In 32fe472 a quite significant change was made to the FUSE setup call. This setting apparently means that chmod on yas3fs mounted directories and files now returns EPERM instead of failing silently. This change can now be undone with the --no-default-permissions switch but this is not documented anywhere, I had to discover this by reading the source.

In my case, this is important for my application as it attempts to chmod and throws an error when the EPERM is returned, even though the permissions are sufficient for the application to work with the previous silent failure. This is strictly my fault for running master instead of a tagged release (I was on master because I also need other fixes that are not present in 2.3.5) and I figure that this may affect other users of yas3fs if/when a tagged release of 2.4.0 is made if it is not documented first.