Added Query::indexBy
fixed the "only" option for FileHelper::findFiles()
Added readme and license files to extensions.
Rewording
Added autoload command.
renamed autoload to classmap.
Merge pull request #614 from suralc/extensions-readme

Add readme and license files to extensions
import namespaces.
Merge branch 'master' of github.com:yiisoft/yii2
import namespaces.
handle array in importNamespaces.
Merge branch 'master' of github.com:yiisoft/yii2
Update migration.md. Fix missed quotes
Merge pull request #617 from aivus/patch-1

Update migration.md. Fix missed quotes
Add echo into docs for link pager

I'm not sure if echo should be mentioned, but without the echo before the LinkPager::widget() the user would see nothing.
Merge pull request #619 from philippfrenzel/patch-1

Add echo into docs for link pager
minor doc improvement.
minor doc fix.
added docs description of abstract db types in migration

replaces #618
Merge branch 'master' of github.com:yiisoft/yii2

* 'master' of github.com:yiisoft/yii2:
  minor doc fix.
  minor doc improvement.
  Add echo into docs for link pager
  Update migration.md. Fix missed quotes
  handle array in importNamespaces.
  import namespaces.
  import namespaces.
  renamed autoload to classmap.
  Added autoload command.
  Rewording
  Added readme and license files to extensions.
  fixed the "only" option for FileHelper::findFiles()
  Added Query::indexBy
  Improved FileHelper::filterPath()
  Enhanced file options for FileHelper.
  Fixed locale command.