Add KWElement() function.
Add KWElement() function.

Provides a friendlier wrapper for Element and is useful as a return
value for functions that wrap individual tagname. This commit also
improves the rationality of argument testing the testing to see if
certain arguments are dict-like (hasattr(thing, 'item') instead of
isinstance(thing, dict). Also added space separator between rulesets
emitted without indentation.

Michael-F-Ellis/htmltree