[bluez] gdbus: use caller's bus name in polkit authorization check

Use the message sender's bus name instead of bluetooth daemon's own
bus name in polkit authorization query.

Added the message as a parameter to GDBusSecurityFunction so that the
sender name (and possibly other message characteristics) can be used
for authorization.
[bluez] jolla plugin for D-Bus access check

Implement a security plugin for checking D-Bus caller authorization.

The effective gid of the calling process is compared against a
configurable list to determine whether the process is authorized to
call restricted D-Bus methods.

By default, in the absence of authorized group configuration, all
callers are authorized.
[bluez] restrict sensitive D-Bus methods to authorized callers

Prevent calls to the following methods from non-authorized callers:

    org.bluez.Adapter.SetProperty
    org.bluez.Adapter.CreateDevice
    org.bluez.Adapter.CreatePairedDevice
    org.bluez.Adapter.CancelDeviceCreation
    org.bluez.Adapter.RemoveDevice
    org.bluez.Adapter.RegisterAgent
    org.bluez.Adapter.UnregisterAgent

    org.bluez.Device.SetProperty
    org.bluez.Device.Disconnect
Merge pull request #50 from hmallat/dbus-privilege-check

Dbus privilege check