[whatwg] [html5] contenteditable specification

[fora at annevankesteren.nl]

In agreement with Ian I started working on figuring out how contentEditable
exactly works and writing it down. This is not what is going to end up here:
 <http://whatwg.org/specs/web-apps/current-work/#the-contenteditable>

This is mainly describing how it is currently implemented in Internet Explorer:
 <http://annevankesteren.nl/projects/whatwg/spec>

Not all things I found out are in that specification and not all is correct.
Some parts of it should probably be rewritten to talk about nodes instead of
elements et cetera, but as I'm not that familiar with the DOM yet it is
currently solved this way.

The plan is take this specification when it is ready and make something more
sane out of it that can be used in HTML 5.

All comments are welcome. I would really appreciate it if you have replacement
texts for the parts that are not very well defined, but I understand time is
limited.