Calling method `checkRequirements` for Controls

[zeleznypa]

• bug report? no
• feature request? yes
• version: 2.3.x

Description

There is a method checkRequirements() in file PresenterComponent.php which is great for Auth operations and also for some Status checks. It will be usefull IMHO, to call this method also for Nette\Application\UI\Control which extends the PresenterComponent class. For example in process of registering component in ContainerTree

[JanTvrdik]

You can easily implement this yourself by simple overriding method validateChildComponent().

[xificurk]

Possible duplicate of #158