Squashed 'cookbooks/mysql/' changes from ae43f6c..8d6a8d2

8d6a8d2 bumping for devodd
8ecad95 fixing rubocops
970d52b Publish 5.2.12 Changelog
a7b3f01 Version bump to 5.2.12
56908a9 PR #192 - recipes/server.rb should honor parameter node[mysql][version]

git-subtree-dir: cookbooks/mysql
git-subtree-split: 8d6a8d237580219113ea8c07227e5b81baaccd4c
Merge commit 'd176aa9d4985bc716c4993d4a37d3ea6078092f8'
add system setting to mysql