README.md: Unify and shorten Y2R dependency descriptions
README.md: Add more Y2R dependencies
README.md: Sort Y2R dependencies needed by modules alphabetically
README.md: Explain why yast2-storage is needed
README.md: Explain why yast2-ldap is needed
Merge pull request #299 from yast/readme-add-even-more-deps

[Review] Request from '' @ 'yast/ycp-killer/readme-add-even-more-deps'