package/tvheadend: use wizard mode on first run

package/tvheadend: use wizard mode on first run

The format of the ACL database in tvheadend has changed, and generating
a default user is a little bit more involved than just dumping a file in
the correct locations: filenames are now md5sum (of something?) and the
usernames and passwords now have their own DB.

However, tvheadend has a wizard mode, where it is possible to configure
the basic features, of which creating an admin user.

We remove our canned ACL database, and change the startup script to
start in wizard mode on first run. We also switch to using our infra to
set the permissions.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>