Add CONTRIBUTING.md

See:

  * https://github.com/blog/1184-contributing-guidelines
  * http://lists.opensuse.org/yast-devel/2013-10/msg00052.html
properly crypt the password for the initial user

- 3.1.2
Merge pull request #23 from yast/cryp_passwd

properly crypt the password for the initial user
Merge branch 'master' into require_root_password

Conflicts:
	package/yast2-users.changes