Fix #14 allow linking to things with '.' in name

Yes, see title.

So I've been under the influence of the thought that characters like '.' were invalid in IDs.  But apparently, HTML5 up and removed almost all the restrictions, as per http://mathiasbynens.be/notes/html5-id-class

That and a little SO lets me now link to namespaced methods, etc.  I'd be surprised if this works in, say, IE9, but shouldn't really harm anything there either; broken things stay broken, but new cool browsers can generate linkable docs with namespaced things.