We can just use a GTask to handle the detection while using the
finish function to process the results to the image, so that it
is more predictable when this happens and it does not depend on
a thread returning.
Also remove data duplication when possible, this class wasn't
fully safe anyway to be used concurrently, so there's no point
to copy data when not needed. Also added the hard constraint to
not proceed with minutiae detection if something else is already
doing this.
At the same time we can mark the task to finish early on
cancellation.
And activate perimeter points removal if this flag is set
This flag should be set for aes1610, aesx660, aes2501, aes2550
and upektc_img since these sensors may produce incomplete image.
Fixes: #142
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.
