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.

attribute:type:Header should also affect sort link

* 'master' of github.com:yiisoft/yii2:
  set default format for gridview to text

correct creation of new Sort object if none is there

set default format for gridview to text