lib: Major rewrite of the libfprint core and API

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.

libfprint/fp-image-device.h

@@ -0,0 +1,29 @@
+/*
+ * FpImageDevice - An image based fingerprint reader device
+ * Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#pragma once
+
+#include <fp-device.h>
+
+G_BEGIN_DECLS
+
+#define FP_TYPE_IMAGE_DEVICE (fp_image_device_get_type ())
+G_DECLARE_DERIVABLE_TYPE (FpImageDevice, fp_image_device, FP, IMAGE_DEVICE, FpDevice)
+
+G_END_DECLS