Do logging direct to journald.

This has the advantage of meaning that the origin process name will be correct
provided it goes through this codepath: fprintf won't work, because if a process
starts children (like e.g. a homescreen does), then their stdout/stderr are
merged into their parent, and journal has no way of differentiating the origin.

We are also able to store information about the context of logging, which might
be useful in post-mortem cases.
always use connman to connect to cellular services

connman provides better error messages.
update the network configuration list when changes in the networks
happen.
add NetworkSessionRequired to connman caps.

This allows QNetworkAccessManager::get(..) to make a connection,
instead of failing.
make sure to signal only changed configurations

really use this
[connmanengine] On configuration removal, take it away from foundConfigurations

Prevents derefence of freed QNetworkConfigurationPrivate pointer in
QConnmanEngine::getConfigurations().
make QNetworkConfiguration Discovered dependent on autoconnectable service

This stops seemingly automatic use of a non autconnectable service,
and allows the connection dialog to popup.
Implement some simple basic theme hints.

We need to do this here, not QtWayland, so that all applications get them.
QtWayland uses QGenericUnixTheme.
make 'AlwaysAsk' if found help determine whether the configuration is
Discovered or not.

Since bearer has no idea about user interaction, we just do this,
and make the roaming/always ask scenario unavailable.