In order to be able to test the private device code (used by drivers) we
need to have that split a part in a different .c file so that we can compile
it alone and link with it both the shared library and the test executables.
Redefine fp_image_device_get_instance_private for private usage, not to move
the private struct as part of FpDevice.
At the end of enroll, the image device would put the driver into the
AWAIT_FINGER_ON state and then deactivate the device afterwards. Doing
this adds additional complexity to drivers which would need to handle
both cancellation and normal deactivation from that state.
Only put the device into the AWAIT_FINGER_ON state when we know that
another enroll stage is needed. This avoids the critical state
transition simplifying the driver state machine.
Fixes: #203
Fixes: 689aff0232
This is the same logic we apply to fp-device by default: any completed
action should trigger the subsequent one when it is finished.
So in case we want reactivate after a deactivation, let's do it in an idle,
after removing the current pending timeout.
This is a rewrite of the core based on GObject and Gio. This commit
breaks the build in a lot of ways, but basic functionality will start
working again with the next commits.
