Define DocType on render.

Added all doctypes as per http://www.w3.org/QA/2002/04/valid-dtd-list.html to Document class.
Added references to HTML type doctypes from Document class constants to Html class for convenience.
If doctype is supplied replace current doctype if it exists before prepending doctype.
Added some comments for completion.
Another approach at replacing the doctype.

It appears that we can loadHTML the <!DOCTYPE and then use name, publicId and systemId to populate the DOMImplementation->createDocumentType().
This doctype can be used to replaceChild of the current document's doctype.
Returning saveXML formats the html5 empty doctype better and it is much less nurve wrecking to preg_replace the <?xml version="1.0" encoding="iso-8859-1" standalone="yes"?> than a doctype.
Both this and the previous commit solves the problem, I might lean towards this option more.
Fix thumb print.

The buck might as well stop here. Attempt to keep transparency with contributors list, thanx goes to Henrique Moody. It's a honour to be on board.
PSR Correction

- Make the structure IF follow the PSR
Merge pull request #31 from malukenho/patch-1

Coding standards fix to conform PSR-2.
Merge pull request #24 from nickl-/render-doctype

Define DocType on render.
Allow Pseudo Selectors

I think that cover pseudo selectors in css template engine Respect is
very handy.
To do this, I created 2 methods in the class `Query` that comes if there
is a pseudo selector in
css selector and passes to a factory that will return the instance of a
pseudo selector and will
call the `apply` to "filter" the dial, leaving compatible with xpath.

Only did the 'first-child', do not know if this is the best way for such
a task.
Hopefully opinions and suggestions.