MT#4955 Only allow one ss, set dom-pref np-display

If a sound set is contract default and you create another default one,
the old gets non-default.

Properly handle contract default setting also when editing sound sets.

And while at it, set np-display as outbound-from-display-name dom-pref
when creating a PBX domain.
MT#5009 Properly re-use free numbers.

Don't try to insert a number into billing.voip_numbers directly,
rather than using the update_subscriber_numbers helper, which
handles the re-using of free numbers.
MT#5009 Properly free voip_numbers on termination.

Don't delete voip_numbers (which was forgotten if the status
got set to terminated anyways), rather than free them by
undef'ing the subscriber_id and reseller_id.
MT#4967 Filter system information for subs-roles

Don't display internal information to subscribers and subscriberadmins.

WIP, as subscriberadmins can now add/change numbers, set lock/status.
Bump debian version to 1.1.4 for 3.1 release.
MT#5009 Properly reuse alias numbers also.

Previously, we assumed they were already deleted in billing.voip_numbers,
which they're not (anymore).
Bump debian version to 1.1.5 for 3.1 release.
MT#5009 Fix syntax error.
MT#5009 Use proper alias number sub-elements.
MT#4235 Implement static Jitsi provisioning.

Should be reworked in a next step to use the dynamic configuration
management, but currently you'd need a PBX device for that, so keep
it static for now.
MT#4967 Show primary number in subscriber list

The wrong relation was used here. Discovered during testing for ticket
MT#4967.
MT#4967 Let subadmins steal numbers

A subadmin can use the field alias_select to select any number of alias
numbers, which he is allowed to manage. If he selects one, it moves
to this subscribers alias_numbers. If he unselects one, it moves to his
own alias numbers.