Better SVG minification

[wooorm]

When embedded in HTML, attributes can be left unquoted (but apparently they can't collapse), also: the SVG element is an HTML element, whereas elements inside it are in the SVG space.

[wooorm]

Collapsing works:

<p>
  Period<svg viewBox="0 0 1 1"width="2"height="2"><rect x="0"y="0"width="1"height="1"/></svg>
</p>

Unquoted works:

<p>
  Period<svg viewBox="0 0 1 1" width=2 height=2><rect x=0 y=0 width=1 height=1 /></svg>
</p>

Everything works!