Adding two options required for compatibility with 3rd party components

New Options :

* implicitHtmlNamespace = Allows the use of createElement instead of
createElementNS for HTML elements. This is required for compatibility
with PHPPowertools/DOM-Query and for compatibility with
symfony/CssSelector.

* target = allows an existing DOMDocument (or subclass thereof) to be
passsed to the DOMTreeBuilder instead of creating a new one. This
option is required for compatibility with PHPPowertools/DOM-Query