MT#7935 Show callid, cost and link to callmap.

In call history of a subscriber, link to callmap, and show the
call-id and source customer cost in case of admin/reseller.
MT#7941 Fix handling empty destination set in pref
MT#7943 Don't access undef provisioning subs.
MT#7797 API: allow list in customer status filter

Use comma-sparated list to filter for certain stati.
Use not_status filter to exclude certain stati.
MT#7941 Another fix for empty CF dsets.
MT#7747 API: implement fee bulk upload

You can now do a POST to /api/billingfees/?billing_profile_id=xx
with Content-Type text/csv, and it will try to parse and insert
the file like the panel does on file upload.
MT#7747 API: Improve fee bulk upload documentation
MT#7747 Make sure to not store purge_existing
MT#7867 Repeat behavior of embedded image on "Change Image" button.

Also added functionality to convert link to embed image, but it
doesn't work on cross-domain links.