gh-10: add script to grow root fs
gh-10: add script to grow root fs

Uses growpart from cloud-utils and supports ext4 and xfs

ungleich/addon-context-linux,OpenNebula/addon-context-linux,baby-gnu/addon-context-linux,ungleich/addon-context-linux,fasrc/addon-context-linux,puppetmaster/addon-context-linux,puppetmaster/addon-context-linux,fasrc/addon-context-linux,OpenNebula/addon-context-linux,baby-gnu/addon-context-linux