[themes] theme function documentation (rephrased froward from dev and doc)

[drupal]

> The base idea is to make something like "unit" html snippets for each
> function. It can't be 100% automated - I need the descriptions. I'll
> prepare the code, but I might need help to add to the argument
> descriptions if this is to be done quicker. 
Although, having said that, if each module was exposing information
about the defined theme_ elements in an _info() fashion, this can be
automated like a breeze.