HTML --> HTML5
empty elements do not have to be closed
support children
static constructor for easy construction with children
add html5 text
automatically escape html text
introduct BuilableInterface
allow all Buildables to be added as children of Element
replace static html with PHP HTML5 Elements
introduce Node
introduct Node::hasChild
Node::getParent --> Node::hasParent
Node::adopt should adopt parent instead of child
make Element and Text extend on Node
wrap withChildren around addChild method
move Element and Text under Node namespace
add HTML5 Document
require root node in Document
use HTML5\Document in index test