Support xmerl data structures

[cinova]

erlsom parses XML and generates lists and tuples for tags, attributes, content, tail, etc.

It would be nice if exemplar could support this by taking an erlsom data structure and spitting out XML.

[oubiwann]

In fact, what I'd like to do is make this the default internal representation for Exemplar markup data. Then, only when asked, should it convert this internal data to string values.

[oubiwann]

See also:

• https://github.com/lfex/lxml

[oubiwann]

Additionally, it would be nice to be given erlsom XML data, parsed to a regular LFE data structure, and then use that to generate Exemplar forms (in other words, support full circle).

[oubiwann]

Okay, some big changes coming in exemplar -- fortunately, nothing that breaks backward compatibility -- if anyone sees anything that breaks, please report! It's a bug!

Here's the commit that brought in the big code changes:

• b3c84ac

I'll document this shortly, but in essence, this lets one treat an entire XML/HTML document as data -- no immediate conversion to string. This will allow us to do some cool things with HTML document (and document fragment) composition -- hello templates!

I'll begin updating the docs and trying this work out on a new version of the LFE docs site ...