HttpKernel Component

We need some documentation for the above component. There's not much more than @fabpot articles on building a framework on the subject.

Current references:
https://github.com/symfony/HttpKernel#readme
http://fabien.potencier.org/article/59/create-your-own-framework-on-top-of-the-symfony2-components-part-6
http://fabien.potencier.org/article/59/create-your-own-framework-on-top-of-the-symfony2-components-part-10

[wouterj]

You can always read the short description in the readme of the component, but this is needed.

@weaverryan this should get an Actionable and components label.

[richardmiller-zz]

I have some notes towards this I can start writing up. @weaverryan you mentioned at some point you were looking at this, have you done some work towards it already?

[wouterj]

@weaverryan this can be closed as you write a great article about this in #2064