By default, FUSE prohibits file access [1] by users other than the one
that mounted the file system. This is a security feature. In order to
use WCFS in multi-user deployments, where other users need to access WCFS,
we therefore need to explicitly set the 'allow_other' FUSE option. This
patch allows setting this option with a new WCFS flag. Besides setting
the flag, it's necessary to add 'user_allow_other' to '/etc/fuse.conf'.
Otherwise the flag is effectless.

[1] See 'allow_other' option at
    https://www.kernel.org/doc/html/latest/filesystems/fuse.html