The interface is designed so that the agents can use it even when Akonadi
is compiled without KAccounts support, so we don't have to clutter all
agents code with #ifdefs. When KAccounts support is compiled in, the class
registers org.kde.Akonadi.Accounts interface on DBus which akonadi_control
uses to tell the resoure about the KAccounts account.
It also provides a simple wrappers to retrieve the OAuth tokens or
In the future this interface will require a wider API to allow accessing
more of the account configuration (e.g. DAV server URL, paths etc.),
but this should be good enough for now.