The parser now kinda recognizes immediate child selectors, !important,
and various other little things.
It's still extremely far from robust and/or correct. :^)
This patch adds parsing of <img> into HTMLImageElement objects.
It also adds LayoutImage and its parent class LayoutReplaced, which is
going to represent CSS "replaced elements."
This patch implements basic support for presentational hints, which are
old-school HTML attributes that affect style.
You add support for a presentational hint attribute by overriding
Element::apply_presentational_hints(StyleProperties&) and setting all
of the corresponding CSS properties as appropriate.
To make the background color fill the entire document, not just the
bounds of the <body> element's LayoutNode, we special-case it in the
HtmlView::paint_event() code for now. I'm not entirely sure what the
nicest solution would be, but I'm sure we'll discover it eventually.
You can now query Document::title() to get a String containing whatever
is inside the document's <title> tag.
In support of this, this patch adds the <html>, <head> and <title>
elements.
Also remove the color values from the ComputedStyle object and get them
via StyleProperties instead.
At the moment, we only handle colors that Color::from_string() parses.
