Fixed Faces malfunction when PhotoImageView size allocation changes.

- The faces weren't be showing at the correct place when you changed
the size of the PhotoImageView, for example changing the size of the
sidebar.
Fixed error in FaceStore.GetFaceById.

- Type of parameter `id` must be `uint`, not `int`.
Fixed faces deletion management.

- Now if all the face locations of a face are deleted the face will also
  be deleted. And if a face is deleted all the face locations
  of that face will be deleted too.
Fixed wrong name in file header.
Corrected/added file headers with autor, copyright and license info.