* origin/pr/61:
update-proxy: use curl instead of wget in archlinux in order to limit additional dependencies
archlinux: properly add qubes markers in pacman.conf
archlinux: add Qubes Markers in pacman.conf so that changes done by qubes scripts are not inserted at the end of pacman.conf
implement update proxy support for archlinux
archlinux: add gcc and make as make dependencies
update qubes.InstallUpdateGUI to support archlinux