We prefixed them with fp- which is not as obvious as fpi-. Also,
explicitly mark them as private and to be skipped in the GObject
Introspection annotatinos.
Warning: FPrint: (Signal)fp-image-device-state-changed: argument object: Unresolved type: 'FpiImageDeviceState'
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.