authz: add QAuthZListFile object type for a file access control list
Add a QAuthZListFile object type that implements the QAuthZ interface. This
built-in implementation is a proxy around the QAuthZList object type,
initializing it from an external file, and optionally, automatically
reloading it whenever it changes.
To create an instance of this object via the QMP monitor, the syntax
used would be:
If "refresh" is "yes", inotify is used to monitor the file,
automatically reloading changes. If an error occurs during reloading,
all authorizations will fail until the file is next successfully
loaded.
The /etc/qemu/vnc.acl file would contain a JSON representation of a
QAuthZList object
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>