Fixes #2435: CFileCache entry expiration time could now be embedded into the cache file.
Merge branch 'master' of github.com:yiisoft/yii into fixes-2435-CFileCache-enhancements

Conflicts:
	CHANGELOG
PHPDoc fixes and better $embedExpiry property naming.
Fix unit test.
Merge pull request #2444 from resurtm/fixes-2435-CFileCache-enhancements

Fixes #2435: CFileCache entry expiration time could now be embedded into the cache file.