Original patch by Daniel Ehlers <danielehlers@mindeye.net>

For security reasons we should not accept incoming packets per default
and instead allow specific services on specific interfaces.

/lib/gluon/release had been lost during the conversion to the new site config
format.

gluon-autoupdater: Always allow forced autoupdate.

On nodes with autoupdate disabled the cmdline parameter '-f' has no
effect. But using the autoupdater for manual updates is quite handy.

gluon-alfred: replace announce.sh with lua script

Closes #20

An undocumented feature of uci:get_first() is to cast the returned value
to the same type as the default argument. Thus, supplying a default
value ot type number makes string.format superfluous.