Some small optimizations to these file builder modules.
Need to differentiate between a tag with a closing tag, and a self-closing tag -- can't just assume that if the serialized child nodes is an empty string that it's ok to have no closing tag, since this doesn't work with some HTML tags.
The first phase of the new widget template compiler... Finally! This has been lurking in the back of my head for too many years already.
First proof test of the new widget template file type (.htmlt).