Package alterator-users: Information

- set UID when writting an avatar in the user's dir
- add check for image type and symlink nesting
- fix avatar display

- fix saving the avatar in the user's root dir
- add an avatar setting to the "pixmap" of the button
- view the image the full resolution by clicking on the button with the avatar

- add utility to move avatars
- backend: add setting and getting user avatar
- add user avatar support to ui
- add user avatar support for net version
- add copy folder with avatars