Drawing 0.4.1

Version 0.4 introduces a new icon, numerous bug fixes, an improved toolbar for the "legacy" and "toolbar only" layouts, an action for creating an image from the clipboard content, a smoother pencil, and various new translations.

Be careful, despite an installation without errors, the deb package is not compatible with Ubuntu 18.04, Debian Buster, elementary Juno and their derivatives: python3-gi needs to be the version 3.30 or more. It can however be installed on Debian Sid and Ubuntu 19.04