Suggest available versions if the requested version don't exists

Suggest available versions if the requested version don't exists
Merge branch 'master' of https://github.com/opscode-cookbooks/mysql

Conflicts:
	libraries/helpers.rb
Suggest available versions if current is not available for current platform.
Merge pull request #270 from sekipaolo/suggest_versions_if_not_available

Suggest versions if not available