boot.crypto, boot.crypto-early, boot.lvm no longer exist

So there is no point in calling insserv with that names as those
init scripts were replaced by systemd generators.
adapt rakefile to use yast rake config
Merge pull request #11 from crrodriguez/master

- boot.crypto, boot.crypto-early, boot.lvm no longer exist
- added changelog entry for merged pull request
- adapted to device-mapper device name changes (bnc#810840)
- additional subvolumes for btrfs root (fate#316222)
add license text
remove useless README
Revert "remove useless README" as there is more readmes

This reverts commit 4632241e1392bec68208cc60f84b25dd9d1da303.
- set values for snapper number cleanup (fate#316233)
- more compact code
- adapted to minor space calculation fix in libstorage
propose to create bios_grub partition on gpt disk for non-EFI systems (fate#315972)
changelog entry
- simpler code
- simpler code
- handle device name change during update due to switch from dmraid to mdadm (fate#316007)
- fixed typo
Add CONTRIBUTING.md

See:

  * https://github.com/blog/1184-contributing-guidelines
  * http://lists.opensuse.org/yast-devel/2013-10/msg00052.html
- changed technique to ensure UTF-8 string in ruby (bnc#848812)