context: Log version number at startup

Having this should at least give us a slightly better idea about the
version that the user has installed. Obviously it is still not very
accurate (maybe a git hash would be good if available?), but it should
still be helpful overall.

libfprint/fp-context.c

@@ -361,6 +361,8 @@ fp_context_init (FpContext *self)
   FpContextPrivate *priv = fp_context_get_instance_private (self);
   guint i;
 
+  g_debug ("Initializing FpContext (libfprint version " LIBFPRINT_VERSION ")");
+
   priv->drivers = fpi_get_driver_types ();
 
   if (get_drivers_whitelist_env ())