Squashed 'libraries/admin/' changes from afd44f5..3714fc0

3714fc0 Merge pull request #111 from wilwade/patch-1
9e975e6 Typo: Extra L

git-subtree-dir: libraries/admin
git-subtree-split: 3714fc00da7c296f4c5f4467cbe38e056d7dd4b4
Merge from yii2-admin