Merge pull request #32 from andreas-schwab/master

Add boot support for aarch64
improved git2log script
added 'archive' target to Makefile
add grub2-mkpasswd-pbkdf2 to inst-sys (bnc 900358)
updated git2log script
- follow rubygem package renaming
- ignore dependency on rubygem-yard
Merge branch 'sle12'
aarch64: move kernel and initrd to boot/aarch64/loader