* TimeZone: autoinstall and API
Add support for Get/Set timezone methods. Get means that we inquire
with GeoIP as to which timezone is suggested. Non-availability of
GeoIP, or a previous explicit Set, means that we return the system
timezone. Set of timezone by Post results in set of the live system
timzeone, and queuing a set of the target system by way of cloud-init.
* Add clarifying comment about _request.
Move mock_app to common location.
Move run_coro to subiquitycore so that subiquitycore doesn't have to
reference things in subiquity, even for test.
Move task tracking things from mirror to geoip.
Server app owns the geoip instance.
Create EventCallback as an alternative to MessageHub that should
hopefully express clearer intermodule dependencies.
Michael Hudson-Doyle