add page start-forms.md
Grammar fix
add start-looking-ahead.md
pull origin
Merge from yiisoft
Merge branch 'master' of github.com:yiisoft/yii2
Fix url
Merge pull request #4588 from marsuboss/patch-1

Fix url
Upgrade jquery.inputmask to v3.0.59
Added validation js callbacks

- `beforeValidateAll`
- `afterValidateAll`

fixes #4234, close #4559
Merge pull request #4589 from thiagotalma/inputmask

Upgrade jquery.inputmask to v3.0.59
Replaced backslashes with forward slashes in template path example [skip ci]

Backslash after alias causes 'Invalid path alias' exception in `\yii\BaseYii::getAlias`
Fixes #4600
Merge pull request #4601 from SDKiller/patch-1

Replaced backslashes with forward slashes in template path example [skip...
Update docs for clientValidateAttribute()
Merge pull request #4603 from Skysplit/patch-1

Update docs for clientValidateAttribute()
Fixes #4591: `yii\helpers\Url::to()` will no longer prefix relative URLs with the base URL
Merge branch 'master' of git://github.com/yiisoft/yii2
fixed random rbac testing failure.
Fixed traslation mistake