[commhistory-daemon] Remove OldDataDeleter

Contrary to the name, this actually only deletes old (90 days) calls.
The implementation is strange, the time is much too short, and the whole
concept is probably unnecessary when using a sane database. If it is
necessary to trim old data out of the database, it should be done more
generically with support for conversations as well, which is much more
important size/performance-wise anyway.
[commhistory-daemon] Port to libcommhistory 1.6.0

Matching API changes in libcommhistory 1.6.0, particularly related
to the switch away from Tracker.

AccountSpecificCallModel was removed in favor of a new account filter in
CallModel itself.
Merge pull request #13 from special/sqlite-backend

Port to libcommhistory 1.6.0