Proposed mutex extension.
Uncomment UNIX Mutex.
Mutex extension docblocks and several minor fixes.
composer.json file and proper class files location.
Proper files location.
Mutex cache backend WIP.
Autorelease callback improved, composer.json typo.
Autorelease callback.
Fixes:

1. Proper auto release shutdown callback.
2. Proper Mutex::releaseLock() method.
Mutex WIP.
Merge pull request #597 from Agrumas/master

Corrections in docs and Model::loadMultiple fix
started controller docs
moved autoloader notes to internals
fixed controller example
Added Formatter::format().
Added DetailView.
Merge branch 'master' of github.com:yiisoft/yii2
Docs on caching:

1. Remove unnecessary samples.
2. Add configuration file location note for basic application.
3. Fix a couple of typos.
Merge branch 'master' of github.com:yiisoft/yii2
Merge branch 'master' of github.com:yiisoft/yii2 into mutex-10050