add page start-forms.md
Grammar fix
add start-looking-ahead.md
pull origin
Fixes #4425: generate cookie validation keys in local config files.
Fixes #4571: ignore non-string attribute names for AttributeBehavior.
Added client-side image validation
Fix lines
Abort further validation if there are no files to validate
Fixes #4566: Added client validation support for image validator
renamed function name [skip ci]
Merge from yiisoft
Merge branch 'master' of github.com:yiisoft/yii2
minor fix [skip ci]
fix typo in define $flavors['gfm-comment']

fix typo Markdown->GithubMarkdown in $flavors['gfm-comment']
Merge pull request #4580 from verysimplenick/master

fix typo in define $flavors['gfm-comment']
Enh #4581: Added ability to disable url encoding in `UrlRule`.
Merge pull request #4582 from tadaszelvys/4581-urlrule-encode-params

Enh #4581: Added ability to disable url encoding in `UrlRule`.
Fix url
Merge pull request #4588 from marsuboss/patch-1

Fix url