FAI-CD: Add Grub2 background image + DejaVuSansMono font.#124

dzatoah wants to merge 2 commits intofaiproject:masterfaiproject/fai:masterfrom

dzatoah:mr/add-background-image-and-font-to-grub2-memdiskdzatoah/fai:mr/add-background-image-and-font-to-grub2-memdiskCopy head branch name to clipboard