V1.6.3

Added

• Package build script for (Fedora, Ubuntu)
• Distro-specific docker-based tests, to test in clean environments (Fedora, Ubuntu)
• Build script to build all supported packages (Fedora, Ubuntu)
• arctis-manager: added --daemon-only option (mainly for test purposes, but can be used to disable the UI)
• VERSION.ini to better store the version and the release
• Systemd dependencies on graphical.target instead of default.target