module should extend \yii\base\Module as \yii\web\Module doesn't exist...

If this is outdated, then pls just ignore it!

- cleanup API and usage, add documetation link
- introduced @property feature in getter or setter which has precedence
  over @return or @param tag if present

* 'master' of github.com:yiisoft/yii2:
  refactored code.

fixes #822

fixes #811

commit in redis branch was:
0cd65e74

Gridview and DataProviders: Autoconfig sorting

Blowfish cost must be in range 4…31, not 4…30

`generateSalt` parameter validation fix.