expose type, color references in DOM for debugging

[amitu]

Can we make this:

-- ftd.text: hello_h0
type: $fpm.type.body-small

Generate the following:

<div data-type="$fpm.type.body-small" style="...">hello_h0</div>

type, color etc we would put the final values in style, but we want "notional" name as data-type etc so we can easily debug.

We may want to do this in debug builds only. We will need a concept of debug builds.