libmsc: Track and update the location update expiry

Set the subscriber expiry timeout to twice the duration of the location
update period and provide functions subscr_expire() and
db_subscriber_expire() to mark subscribers offline that have missed two
location update periods.

This patch increases the DB revision to 3, so the hlr will be
incompatible with prior versions.

We should allow 0 for T3212 as well to disable the location update
period. In that case we will need a way to indicate that in the
database.

0 files changed, 0 insertions, 0 deletions